THE JORDAN REPORT ACCELERATED DEVELOPMENT OF VACCINES 2007

U. S. DEPARTMENT OF HEALTH AND HUMAN SERVICES National Institutes of Health National Institute of Allergy and Infectious Diseases NIH Publication No. 06-6057 May 2007 www.niaid.nih.gov

Images on cover, clockwise from top: © The World Bank; Courtesy of the National Library of Medicine; istock.com; Courtesy of the National Library of Medicine

Table of Contents

INTRODUCTION VACCINE UPDATES Introduction by Carole Heilman, Ph.D...... 3 Supporting the Nation’s Biodefense ...... 69 Animal Models for Emerging Infectious Diseases Tribute to Maurice R. Hilleman, Ph.D., and John R. La Montagne, Ph.D., by William S. Jordan, Jr., M.D...... 5 Hepatitis C...... 75 HIV/AIDS ...... 77 EXPERT ARTICLES Dale and Betty Bumpers Vaccine Research Center The Immunology of Influenza Infection: Implications Human Papillomavirus (HPV) ...... 87 for Vaccine Development Cancer Vaccine Development at NCI Kanta Subbarao, M.D., M.P.H., Brian R. Murphy, M.D., Influenza ...... 89 and Anthony S. Fauci, M.D...... 11 Malaria ...... 95 Vaccine Production and Supply: Vulnerabilities in the Present System Severe Acute Respiratory Syndrome (SARS)...... 103 Walter A. Orenstein, M.D., Alan R. Hinman, M.D., Streptococcus Pneumoniae...... 109 M.P.H., Lance E. Rodewald, M.D...... 21 The Gambia Pneumococcal Vaccine Trial Project BioShield: A Tool for Developing, Using, and Tuberculosis...... 113 Stockpiling Needed Public Health Emergency Medical Countermeasures Varicella-Zoster Virus...... 119 Noreen A Hynes, M.D., M.P.H...... 27 West Nile Virus...... 123 Using Genomics to Identify Novel Vaccine Candidates Against Pathogens APPENDIXES Hervé Tettelin, Ph.D., Rino Rappuoli, Ph.D., and Claire M. Fraser-Liggett, Ph.D...... 37 Appendix A: Status of Vaccine Research and Development ...... 127 Adolescent Immunizations: Will the Shots Hit Their Targets? Amy B. Middleman, M.D., M.P.H., M.S.Ed...... 43 Appendix B: Vaccines Licensed for Immunization and Distribution in the United States ...... 141 Phase IIB/Test of Concept Trials for HIV Vaccine Efficacy Evaluation Appendix C: HIV Vaccine Candidates in Preclinical Susan P. Buchbinder, M.D...... 53 Development ...... 145 The Animal Rule from a Vaccine Development Perspective Appendix D: Clinical Trials of HIV Vaccine Candidates in Mark J. Abdy, D.V.M., Ph.D., Michael Merchlinsky, Ph.D., and HIV-Uninfected Adults...... 147 Drusilla L. Burns, Ph.D...... 61 Appendix E: Recommended U.S. Childhood Immunization Schedule...... 151 Appendix F: Recommended U.S. Adult Immunization Schedule ...... 155

THE JORDAN REPORT 2007 1 2 THE JORDAN REPORT 2007 Introduction

Carole Heilman, Ph.D. binant DNA. Scientists also continue to additional benefit of the vaccine may be improve existing vaccines and identify to decrease transmission of B. pertussis new vaccine candidates to prevent diseases to infants, who are particularly vulnerable Background for which no vaccines currently exist. By to severe illness from B. pertussis.The t has been almost 25 years since the increasing their understanding of the illness affects 50 million people world­ first vaccine research and development immune system and how it fights off wide each year. I“state of the science” report, otherwise harmful microbes, researchers have also known as The Jordan Report, was pub­ made exciting developments in vaccine Challenges and Opportunities lished by the National Institute of Allergy research methodology, which have Despite considerable progress in vaccinol­ and Infectious Diseases (NIAID), part of resulted in recent clinical trials to evaluate ogy, the emergence of new infectious the National Institutes of Health. Since candidate vaccines against malaria, diseases, the re-emergence of old diseases, that time, significant scientific progress tuberculosis and West Nile virus. and the persistence of intractable diseases has been made in developing new and An exciting scientific milestone (sometimes due to drug resistance), better vaccines against a wide array of occurred in January 2004, when a new make infectious diseases some of the infectious diseases, including those that tuberculosis vaccine entered Phase I most complex and difficult challenges are emerging or re-emerging. clinical trials. NIAID has supported facing the public health community today. Historically, vaccines have led to some research on this candidate vaccine since HIV/AIDS, malaria, and tuberculosis of the greatest public health triumphs ever, its earliest stages. The vaccine was the are still among the leading killers world­ including the eradication of naturally- first to reach human trials in the United wide and no licensed vaccines against occurring smallpox from the globe more States and, in fact, the first new tubercu­ them currently exist. In addition, new than 50 years ago, and the near-eradication losis vaccine to be tested in more than infectious diseases continue to emerge. of polio. In addition, there has been a 60 years. Since the last edition of The Jordan significant reduction in the disease burden Childhood and adolescent vaccines Report, the world has seen an outbreak imposed by measles, mumps, hepatitis, are another area in which significant of a novel coronavirus termed “severe influenza, diphtheria, and many other advances have been made. In March acute respiratory syndrome” (SARS), infections. 2005, global health leaders presented new yearly West Nile virus outbreaks, and This edition of the Jordan Report research findings showing that vaccinating most recently, the continuing threat of a outlines a number of significant advances infants against Streptococcus pneumoniae— potential avian influenza pandemic. made in infectious disease vaccine a bacterium that causes deadly pneumonia, Even as infectious diseases emerge research and development since the last meningitis, and sepsis—could substan­ and re-emerge, however, scientists con­ document was published in 2002. In tially reduce death and serious illness tinue to rapidly develop and design addition, it offers a variety of perspectives among children in the developing world. novel vaccine approaches. These include from experts in the field on timely This study, The Gambia Pneumococcal developing new adjuvants and novel immunization topics, including adolescent Vaccine Trial, was supported in part by delivery systems such as oral, nasal, vaccine platforms and vaccine supply. the NIAID. transcutaneous vaccinations, and com­ In October 2005, study results were bination vaccine strategies. In addition, Advances in Vaccine Research released for the NIAID-supported acellular the application of genomic and post- and Development pertussis trial, which showed that the genomic technologies in the development One factor contributing to the rapid candidate vaccine was more than 90 of a new generation of tailor-made expansion of the current vaccine arsenal percent effective in preventing the trans­ vaccines has the potential to provide a is the acceleration of technological mission of B. pertussis in people between stunning opportunity to “customize” advances, including those using recom­ the ages of 15 and 65. An important vaccines against novel microbes.

INTRODUCTION 3 There is also great enthusiasm and renewed effort for exploring opportunities for vaccine development in less traditional areas. These areas include therapeutic vaccines for managing chronic diseases, vaccines for controlling autoimmune dis­ eases, and vaccines against diseases of particular public health concern that have implications for global health.

Positive Spin-offs of Basic Research NIAID’s investment in research on biode­ fense pathogens will have many positive implications for global public health. Studies of microbial biology and the pathogenesis of organisms with bioterror potential will lead to a better under­ standing of other, more common and naturally occurring infectious diseases and advance future vaccine development pathways and strategies. Furthermore, this research promises to enhance the understanding of molecular and cellular mechanisms (including regulation) of the immune system, which may help in the search for new ways to treat and prevent a variety of immune-mediated diseases such as type 1 diabetes, rheuma­ toid arthritis, cancers, neurological diseases, and allergic and hypersensitivity diseases.

Conclusion While the insightful articles composed for this publication are invigorating and thought-provoking, the complexities, intricacies, and unknowns of host- pathogen interactions continue to pose considerable challenges. Researchers continue to address these obstacles with acute scientific curiosity and intensity. With the expanded commitment and resulting synergy from the federal gov­ ernment, industry, and the scientific community, the pace of progress will undoubtedly lead to unprecedented levels of discovery.

4 THE JORDAN REPORT 2007 Tribute to Maurice R. Hilleman, Ph.D., and John R. La Montagne, Ph.D.

William S. Jordan, Jr., M.D. Dr. Hilleman for help with the diagnosis history. Both science and industry lost a of psittacosis. Several members of a great champion when Dr. Hilleman t has been five years since the publi­ family that had recently purchased a pet passed away in 2005. cation of the 20th anniversary issue psittacine bird at a downtown Cleveland I of this Report. I am pleased to again store were admitted with pneumonia. k introduce the current issue of the Jordan Serologic tests performed by CDC at Report and to join Dr. Anthony S. Fauci, Chamblee, GA, using Lygranum antigen, I first met Dr. La Montagne in 1976, the Director, NIAID, and Dr. Carole and by Dr. Hilleman, using a phenol- year both of us arrived at NIAID. In that Heilman, Director, DMID, in dedicating enhanced lymphogranuloma venereum year he received a baptism by fire as the it to my good and long-time friends, Dr. antigen prepared in his laboratory, new influenza program officer in the Maurice R. Hilleman, and Dr. John R. La confirmed the diagnosis. Years later we Development and Applications Branch. Montagne. These two scientists, both of learned that the psittacosis was not caused An atypical, swine-like influenza virus whom passed away, exemplified the by a virus but by Chlamydia psittaci. had been isolated from a soldier at Fort finest in collaboration and cooperation I saw Dr. Hilleman many times in Dix, NJ, with a fatal respiratory illness. between industry and government. subsequent years, and particularly relished It fell to Dr. La Montagne to find com­ I knew Dr. Hilleman since the early the occasion when I could compliment panies to produce a univalent swine flu 1950s when we were both young investiga­ him for demonstrating that an adenovirus vaccine and to recruit investigators to tors, he at the Army Medical Department (RI67) was the cause of an epidemic test it. Pressure was on because President Research and Graduate School and me disease (later called acute respiratory Ford, after having been advised by a at Western Reserve University as a mem­ disease or ARD) amongst military group of consultants who recalled that ber of the Department of Medicine and recruits. His considerable contributions the virus of the 1918-1919 pandemic Preventive Medicine. The latter was to vaccine research and development at was also associated with pigs, agreed chaired by Dr. John H. Dingle, one of my Merck became legend before and after I that universal immunization to protect attending physicians at the Boston City joined NIAID in 1976 as Director of its against this might be desirable. So many Hospital where I returned to complete Microbiology and Infectious Diseases questions had to be considered: How my residency after World War II. During Program (MIDP, later DMID). It was much vaccine was needed? What part of that war, Dr. Dingle served as Director of natural for Dr. George Galasso, Chief of the population should be vaccinated? the Commission on Acute Respiratory the Development and Applications Branch, Dr. La Montagne did his job calmly Diseases (CARD) at its laboratory at and me to encourage Dr. Hilleman to and thoroughly while respectfully handling Fort Bragg, NC. CARD was under the obtain the attenuated varicella virus the swine flu dilemmas that followed. Armed Forces Epidemiology Board, of developed by Professor Michiak He approached his later assignments which Dr. Dingle was later to become Takahashi of Japan. We offered NIAID’s with the same demeanor. His compre­ President. These activities introduced assistance in conducting clinical trials. hension of issues was always thorough him to Dr. Hilleman and led to his sug­ Dr. Hilleman nursed the virus through and helpful, as was his ability to bring gestion that I call on Dr. Hilleman for the laboratory until he was satisfied with together those sharing his objectives. assistance. the product. Dr. Anne Gershon was then Following my retirement from As the staff member in charge of recruited to coordinate field trials in NIAID in 1987 to continue as a patient care on the Infectious Diseases young, at risk children, receiving Volunteer, Dr. La Montagne succeeded ward of University Hospital, I called on chemotherapy for leukemia. The rest is me as Director of MIDP. The Program

TRIBUTE TO MAURICE R. HILLEMAN, PH.D. AND JOHN R. LA MONTAGNE, PH.D. 5 was given Division status (Division of with having developed more human and of the National Institute of Allergy and Microbiology and Infectious Disease; animal vaccines than any other scientist, Infectious Diseases (NIAID), died sud­ DMID) and, to my surprise, Dr. La helping to extend human life expectancy denly of a pulmonary embolism in Montagne named this periodic Vaccine and improving the economies of many Mexico City, the city of his birth, on Report for me. The premature loss of his countries. He retired from Merck in November 2, 2004. He was 61. talent is indeed tragic. 1984 as senior vice president. John’s untimely passing was a heart­ I am indebted to the Sabin Vaccine Hilleman pioneered the develop­ breaking shock to all who knew him. I Institute and to Dr. Fauci, Director of ment of numerous vaccines, including had known John for nearly 30 years; he NIAID, who prepared and published the measles, mumps, rubella, varicella, was a dear friend and one of the finest following biographies. Marek’s disease, hepatitis A, hepatitis B, people I have ever known. In his long and adenoviruses. He also participated career at NIAID, his accomplishments in in the evolution of vaccines against improving global health—especially In Memory of meningitis and pneumonia. with regard to leading vaccine develop­ Maurice Hilleman, Ph.D. Another important aspect of his ment efforts—were remarkable. On a Vaccinologist of the 20th Century work was advancing the science of com­ personal level, his generosity, wit, even­ Courtesy of the Sabin Vaccine Institute bination vaccines. For instance, the handedness, and kindness made him a combined measles, mumps, and rubella friend to all who knew him, from world A long-time colleague of the Sabin Vaccine vaccine prevents three diseases with only health leaders to the cleaning lady in his Institute, Maurice R. Hilleman, Ph.DSC., one vaccination. Children therefore receive office with whom he spoke Spanish passed away on April 11, 2005 at a hospi­ fewer painful injections and parents and every morning. tal in Philadelphia where he was being children face less anxiety. Pediatricians John received a B.A. (1965) and an treated for cancer. Hilleman was a require less storage space for vaccines M.S. (1967) in microbiology from the microbiologist who developed over three and less handling is required. University of Texas at Austin, and went dozen vaccines for diseases including In March 2005, the University of on to receive a Ph.D. in microbiology mumps, measles, chickenpox, pneumonia, Pennsylvania’s School of Medicine and from Tulane University in 1971 where, and meningitis. His discoveries have the Children’s Hospital of Philadelphia, for his doctoral dissertation, he charac­ saved tens of millions of lives and reached in collaboration with the Merck terized a thermophilic bacteriophage of into every home. Company Foundation, announced the Bacillus subtilis named TSP-1. Upon Though he was not as widely known creation of the Maurice R. Hilleman graduation he worked as a postdoctoral among the general public as some other Chair in Vaccinology. fellow in the laboratory of Julius scientists of note, his achievements match The Hilleman Chair will be occu­ Youngner at the University of Pittsburgh, or exceed many of the greats. Hilleman pied by a physician/scientist contribut­ where his efforts were focused on animal was the fourth scientist to receive the ing to vaccinology on the faculty of virology. He joined NIAID in 1976 as prestigious Sabin Gold Medal, which he University of Pennsylvania and the post influenza program officer; of note, his was awarded in 1997. He maintained a will serve to accelerate the pace of vac­ last academic paper, a commentary pub­ close association with the Sabin Vaccine cine research there. lished in the New England Journal of Institute since then, lending his expertise Medicine also dealt with influenza. In the to Institute programs as a member of mid 1980s, John organized the NIAID the SVI Scientific Advisory Council. In Memory of extramural AIDS Program, and in 1987 Raised on a farm in Montana, John R. La Montagne, Ph.D. was appointed director of the NIAID Hilleman credited much of his success True Public Health Hero Division of Microbiology and Infectious to his boyhood work with chickens, Anthony S. Fauci, M.D. Diseases Program. I appointed him the whose eggs form the foundation of so NIAID deputy director in February 1998. many vaccines. He pioneered the devel­ The infectious diseases community has Throughout his career, John made opment of eight of the 14 routine vaccines lost a trusted friend and ally. My col­ significant contributions to the national and much of modern preventive medi­ league, John R. La Montagne, Ph.D., the and international effort against emerg­ cine is based on his work. He is credited skilled and much-loved deputy director ing and re-emerging infectious diseases.

6 THE JORDAN REPORT 2007 Of particular note, he played a central role in the organization of the Multilateral Initiative on Malaria, chaired the World Health Organization Task Force on Strategic Planning for the Children’s Vaccine Initiative, advised the Pan American Health Organization on their programs in vaccine research implemen­ tation, and led a multinational effort to develop and license acellular pertussis vaccines. John’s career has been lauded by public health leaders around the world, who have expressed their condolences to us by the hundreds. He was, in the words of Tommy Thompson, Secretary of Health and Human Services, a “true public health hero.”

TRIBUTE TO MAURICE R. HILLEMAN, PH.D. AND JOHN R. LA MONTAGNE, PH.D. 7 8 THE JORDAN REPORT 2007 EXPERT ARTICLES

The Immunology of Influenza Infection Implications for Vaccine Development*

Kanta Subbarao, M.D., M.P.H., Brian R. Influenza viruses cause repeated Influenza viruses utilize two mechanisms, Murphy, M.D., and Anthony S. Fauci, infections in humans and are a significant referred to as antigenic drift and antigenic M.D. cause of morbidity and mortality annu­ shift, to evade the human immune ally, accounting for as many as 36,000 response. Antigenic drift is a continuous Introduction excess deaths each year in the United process of change in which mutations he “Spanish Flu” pandemic of States [2, 3], and 250,000-500,000 deaths occur in and around the antibody (Ab)­ 1918-19 spread rapidly across the globally [1]. Influenza is a winter illness combining sites of the HA and NA proteins T globe, killing an estimated 50 mil­ in temperate climates; however, it occurs that allow the virus to escape neutraliza­ lion or more people, many of whom in two seasons or throughout the year in tion by pre-existing Abs. Five Ab-combin­ were young and otherwise healthy. Since tropical climates. Three types of influenza ing sites have been mapped on the HA 2003, highly pathogenic H5N1 avian viruses, designated influenza A, B, and of H3 subtype human influenza A influenza viruses have caused massive C, exist in nature and, of these, influenza viruses [6]; however, less is known about outbreaks in poultry and migratory A and B viruses cause annual epidemics. HAs of avian influenza A subtypes. birds in more than 54 countries. World­ Humans are the only hosts for influenza Antigenic shift is a rare but epidemio­ wide, as of early 2007, approximately B viruses, but influenza A viruses infect logically highly significant event in 270 confirmed cases of human H5N1 a variety of species including birds, which a virus bearing a novel HA, with influenza in 10 countries, including humans, and a variety of other mam­ or without an accompanying novel NA, more than 160 deaths, had been reported malian species such as pigs, horses, cats, is introduced into the human popula­ by the World Health Organization dogs, ferrets, and mice [3, 4]. Influenza tion. A virus bearing a novel HA or NA (WHO) [1]. The H5N1 virus is very A viruses are divided into subtypes has the potential to cause a pandemic if poorly transmissible from person to based on the antigenicity of the two major a large proportion of the population person, but the possibility that the virus surface glycoproteins: the hemagglutinin lacks immunity to the novel HA and NA could become easily transmissible and (HA) and neuraminidase (NA). These and if the virus has the ability to spread spread around the world in a global two proteins are the main targets of the efficiently from person to person. The pandemic similar to that in 1918 under­ protective immune response. The HA is novel HA and NA genes in pandemic scores the importance of rapidly pro­ a trimer with a receptor binding pocket influenza viruses are derived from the ducing a safe and effective pandemic on the globular head of each monomer, reservoir of avian influenza viruses in influenza vaccine. Because a pandemic and the NA is a tetramer with an enzyme nature. H5N1 influenza strain has not yet active site on the box-shaped head. emerged, current efforts, by necessity, Aquatic birds represent the reservoir Pre-existing Immunity Against focus on developing “pre-pandemic” of influenza A viruses in nature. Viruses Influenza vaccines against currently circulating of all known (16 HA and 9 NA) subtypes A redundancy in the immune response to influenza strains. Understanding the have been isolated from waterfowl and influenza allows the humoral and cellular immunology of influenza virus infection shorebirds. However, influenza infections immune systems to act independently to will play a key role in designing effective in waterfowl tend to be asymptomatic, clear an influenza virus infection. Abs vaccines against pre-pandemic and and the viruses are in ecological stasis in present at systemic or mucosal sites at pandemic viruses with the maximum these hosts [5]. In contrast, influenza A the time of infection that are directed at potential for protecting against severe virus infections in humans elicit an the HA or NA protein of the infecting disease and death. immune response that provides selective virus are the major mediators of resist­ pressure and drives the virus to evolve. ance to influenza, whereas the cellular

THE IMMUNOLOGY OF INFLUENZA INFECTION 11 immune response to influenza works H3N2 viruses led to the conclusions that tection of the upper respiratory tract. with the humoral immune response in the HA was under positive selection [9] Third, the ability of the virus to drift viral clearance [7]. Abs directed at the and that two or more amino acid changes and evade immune detection and the HA and NA surface glycoproteins of the in two or more Ab-combining sites of paucity of conserved epitopes on the HA virus are effective in mediating protec­ the HA were sufficient for a virus to evade that induce cross-reactive neutralizing tion that is long lived in the absence of neutralization by Ab against the previously or protective Abs pose a challenge for antigenic drift or shift. This was evident circulating strain [6]. The mechanism by vaccine development. Currently licensed in 1977 when an H1N1 virus that had which Abs protect against influenza virus human influenza vaccines are updated circulated in the early 1950s reappeared infection are indicated in Figure 1. Cellular annually to keep up with antigenic drift in the human population. Significant immunity is directed at epitopes on several that is identified through virologic sur­ disease was only seen in persons born influenza virus proteins, but this immu­ veillance. Fourth, clinical studies have after the H1N1 virus had stopped circu­ nity is relatively short lived [7]. established that two doses of currently lating in 1957, indicating that homotypic formulated inactivated vaccine are immunity is long lived. Because the Vaccine Development required to elicit protective Ab titers in individuals born after 1957 were infected Several important considerations for immunologically naïve individuals. The multiple times with H2N2 or H3N2 vaccine development follow from the live attenuated virus vaccine is significantly viruses that share internal protein antigens interactions between influenza viruses and more immunogenic than inactivated (e.g., nucleoprotein) with the H1N1 the host. First, influenza viruses replicate virus vaccine in naïve individuals. In virus, it was clear that the long-lived extremely rapidly in the host. Peak titers practical terms, each winter, previously homotypic immunity was provided by (which correlate with disease) are achieved unimmunized children should receive Abs and that cell-mediated immunity to before a cell-mediated immune response two doses of vaccine one month apart shared antigens such as the nucleoprotein can be generated de novo or from memory while a single vaccine dose can protect played a relatively small role in resistance. to restrict replication (Figure 2). Therefore, previously primed children and adults. Thus, homotypic Abs are highly protec­ the major goal of the currently licensed tive and mediate significant protection influenza vaccines is to induce Abs prior Pandemic Influenza in humans, whereas Abs to the HA and to infection that function to dampen Preparedness NA of other subtypes and cell-mediated virus replication. Second, influenza is a Recent events in Asia have highlighted immune responses are less effective in respiratory tract infection and Abs the pandemic potential of avian influenza long-term immunity. induced by vaccine that restrict replica­ viruses and the need to prepare for an Heterosubtypic immunity, which tion throughout the upper and lower antigenic shift in influenza A viruses. is protection conferred by previous respiratory tract are desired. Intranasally Although antiviral drugs can be effective infection(s) with an influenza virus of administered live attenuated vaccines in prophylaxis, vaccines are the preferred a different subtype, is weak in humans, efficiently induce a mucosal as well as a strategy for the prevention of a pandemic, especially in children. Recent analysis of systemic Ab response. Mucosal Abs are because pandemic viruses might be epidemiological data collected before more effective than systemic Abs in resistant to licensed antiviral drugs or, and during the 1957 pandemic suggests restricting replication of influenza virus even if initially sensitive, can rapidly that heterosubtypic immunity was in the upper respiratory tract. In contrast, develop drug resistance. A realistic goal observed in adults but not in children parenterally administered inactivated of a pandemic influenza vaccine is to [8]. Definitive data regarding the role vaccines primarily induce systemic prevent mortality and severe morbidity that heterosubtypic immunity plays in (serum) Abs that restrict replication of with acceptance of the fact that infections resistance to influenza virus infection in virus in the lower respiratory tract. associated with mild illness will not be humans are lacking, and the mediators Therefore, inactivated vaccines are effec­ prevented. This requires the development of such immunity in humans have not tive in prevention of severe disease and of vaccines that, at the least, elicit systemic been identified. complications of influenza, but are less Abs of sufficient titer to restrict virus An analysis of genetic and antigenic effective than previous natural infection replication in the lower respiratory tract, data on the HA from human influenza A and live attenuated virus vaccine in pro­

12 THE JORDAN REPORT 2007 thereby preventing pneumonia and its influenza vaccines (H1 and H3 subtypes). along a track that parallels the develop­ associated complications. The amount of HA required in unadju­ ment and evaluation of inactivated virus Although principles that have been vanted pandemic vaccines produced vaccines [19]. The live attenuated pandemic established from basic and applied research with inactivated H5N1 influenza virus influenza vaccine candidates contain the in human influenza can be applied to to elicit a serum Ab response of similar attenuating genes of the A/Ann Arbor/6/60 pandemic influenza vaccine development, magnitude as the licensed interpandemic cold-adapted virus that is the backbone several critical gaps in knowledge remain. influenza vaccine is likely to exceed 15 of the licensed live attenuated influenza For example, the antigenic sites on avian micrograms (mcg). However, in trials of A virus vaccine. Candidate vaccines have HAs and the immune correlates of protec­ the whole-virus or split-virion H5N1 been generated against H5 and H9 sub­ tion from avian influenza virus infections vaccines in which an alum adjuvant was type viruses, and vaccines against the are not known. Additionally, the HA also administered, serum antibody other subtypes will follow. Promising data proteins of avian subtypes of influenza responses that correlate with protection obtained from testing in mice and ferrets A viruses are not as immunogenic as in human influenza were observed when suggest that live attenuated vaccines are human influenza A HA subtypes for patients were immunized with 2 doses suitable candidates for evaluation in unknown reasons; therefore, approaches of 10 and 30 mcg of antigen, respectively Phase I clinical trials for safety, infectivity, to enhance the immunogenicity of the [11, 13]. Results from a Phase I clinical and immunogenicity and such studies avian HA in a pandemic virus may be trial of inactivated H9N2 vaccine are currently under way [20]. needed to achieve a protective level of administered with the MF59 adjuvant The potential of recombinant subunit immunity. Such new approaches will be indicate an immune response of a mag­ DNA, and vectored vaccines to protect needed in addition to the two doses of nitude that correlates with protection against pandemic influenza viruses is vaccine now required to successfully from human influenza in all volunteers also being explored in several preclinical immunize a naïve population. at doses as low as 3.75 mcg [10]. Trials studies. DNA vaccines containing the Currently two classes of vaccines are of an inactivated H5N1 virus vaccine HA and NA genes of avian influenza licensed for seasonal (interpandemic) administered with the MF59 adjuvant viruses and the highly conserved M and influenza in the United States: parenterally are under way. NP viral genes have been shown to delivered inactivated virus vaccines (whole In addition to making seed viruses induce protective immunity in animal virus or subunit) and a live attenuated beforehand and evaluating their safety models [21, 22, 23, 24]. An NP DNA vaccine delivered as a nasal spray. Both and immunogenicity, several important prime-recombinant adenoviral boost types of vaccines are trivalent and contain applied vaccine research issues should strategy using the NP influenza gene an influenza A H1N1 subtype virus, an be explored to ensure the availability of protected mice against lethal infection influenza A H3N2 subtype virus, and an enough doses of appropriately immuno­ by H5N1 virus [25]. Recent studies have influenza B virus to protect against each genic influenza vaccines to protect the also demonstrated that mice and chickens of the co-circulating strains of influenza. population against potential pandemic immunized with a replication-incompetent Vaccines against potential pandemic strains of influenza. These include further human adenovirus vaccine containing the strains of influenza are now being devel­ exploration of known and novel adjuvants H5 HA gene were protected from infec­ oped based on both of these strategies. to enhance immunogenicity; exploration tion with H5N1 viruses [26, 27], and a Seed viruses for inactivated vaccines of ways to reduce the amount of HA recent report showed that vaccination have been generated against influenza antigen required to elicit protective Ab with plasmid DNA containing HA gene viruses of H5, H7, and H9 subtypes. titers by investigating alternative routes of from the 1918 H1N1 pandemic virus Pre-clinical data have been generated for vaccine administration; and consideration protected mice against lethal challenge with all three subtypes, and H5 and H9 sub­ of a strategy of pre-emptive vaccination to the reconstructed 1918 influenza virus type vaccines have been evaluated in prime the population for an Ab response [28]. Although DNA vaccines to protect Phase I clinical trials [10, 11, 12, 13, 14, to a novel HA. against pandemic and seasonal influenza 15, 16, 17, 18]. The investigational H5 Efforts are under way to develop and show great promise and are safe to pro­ and H9 inactivated vaccines are less evaluate live attenuated vaccines against duce, their safety and efficacy in humans immunogenic than interpandemic potential pandemic strains of influenza have not yet been determined. However,

THE IMMUNOLOGY OF INFLUENZA INFECTION 13 a Phase I study of a DNA vaccine con­ isolated in 2004 and 2005, and two doses The development of cross-subtype taining a modified version of the H5 protected both mice and ferrets from HA-based protection requires the identi­ hemagglutinin gene developed by the replication of challenge virus in the res­ fication of conserved sites in the H1-H16 NIAID Vaccine Research Center piratory tract following intranasal HAs that could induce broadly protective, recently began. administration of 2004 or 2005 H5N1 highly functional neutralizing Abs. It is Additionally, cell culture substrates wild type viruses [20]. important to emphasize that such Abs are being evaluated as alternatives to Similar results have been observed are not regularly induced in humans by embryonated eggs for vaccine manufacture. using an inactivated H5N1 virus that infection with influenza A viruses Unpublished results indicate that an protected ferrets from lethality due to belonging to multiple HA subtypes, an inactivated H5N1 vaccine produced in heterologous H5N1 viruses [30]. Further, observation that indicates the difficulty Vero cells appears to be safe and a 1997 H5N3 vaccine protected ferrets of achieving this goal. A recent advance immunogenic in preliminary studies [29]. from death when challenged with a 2004 in this area is the determination of the H5N1 virus [31]. If these vaccines induce crystal structures of the HA from several Harnessing Immunological a broadly cross-reactive immune response additional subtypes of influenza A viruses. Memory in humans, the vaccines may not need to The first 15 HA subtypes fall into 4 Several decades of experience with be updated as the H5N1 viruses evolve clades (2 groups of 2), with H9, H1, H3, human influenza vaccines indicate that in poultry. and H7 being the prototypes of the 4 the vaccine strain must be closely related Clinical studies also offer promise clades [33]. Perhaps the commonalities to the epidemic strain of influenza in that pre-emptive vaccination with an within clades of HA subtypes based on order to be effective. Although the match inactivated H5N1 virus vaccine may HA structure can be exploited to between vaccine virus strains and epidemic generate at least partial, long-lasting develop immunogens and strategies that virus strains is generally good because the immunity that could later be boosted can induce cross-reactive Abs effective evolution of human influenza viruses is with a pandemic vaccine. Researchers among HA subtypes. Another approach continuously monitored through careful, who conducted a trial in 1998 with a to inducing broadly cross-protective global virologic surveillance and vaccine vaccine made from an inactivated 1997 immunity involves (1) identifying con­ strains are updated based on these data, H5N1 virus recently re-immunized served CD8+ T-cell epitopes (Figure 1) we have no basis upon which to predict some of the same patients with a vaccine that can be induced in most members of the exact strain of avian influenza that developed against the 2004 H5N1 virus the population and (2) maintaining the will cross the species barrier and cause a and found that twice as many of the CD8+ T cells in a highly functional state pandemic. This makes it unlikely that revaccinated volunteers developed an that can keep an infecting influenza the pandemic vaccine strain will exactly immune response indicative of protection, virus from reaching high titer in vivo. match the pandemic virus. compared with volunteers who received Maintaining CD8+ T cells in a highly Several recent studies in animal only a single dose of vaccine to the functional state represents a real challenge models suggest that a vaccine that is H5N1 strain circulating in Vietnam in because the genetic program of the similar, but not identical, to a potential 2004 [32]. CD8+ T-cell response is to relatively pandemic strain may offer some protec­ rapidly transition from an activated state tion against serious disease and death. Toward a “Universal” Vaccine to an inactive memory state. The main­ For example, in studies in ferrets and Ideally, a vaccine that provides cross- tenance of CD8+ T cells in a highly mice, live attenuated H5N1 vaccines reactive immunity between the H1-H16 functional state will have to happen in generated from viruses circulating in subtypes of influenza would offer a wider the absence of antigenic stimulus. The 1997, 2003, and 2004 protected against range of protection should an influenza immunogens capable of inducing this H5N1 viruses isolated over eight years virus emerge from a subtype that has type of response have yet to be identified from 1997 to 2005. A single dose of vaccine not previously infected humans. Further but could include sequences from circu­ containing HA and NA gene segments research and development efforts are lating H1 and H3 subtype influenza from the 1997 virus protected mice against required to achieve this goal, some of viruses. Immunization with T-cell vaccines the lethal infection with H5N1 viruses which are discussed below. could provide varying degrees of resist-

14 THE JORDAN REPORT 2007 ance to disease following infection with * This article was adapted with permission from an H5N1 pandemic virus, as well as with Subbarao K. et al., 2006 [36]. circulating H1 and H3 viruses. It is essential to determine the ability to maintain this state of immunity throughout the period of circulation of the first wave of the pandemic virus. The M2 protein of influenza A viruses is highly conserved, and non-neutralizing Abs to the M2 protein protect mice from subsequent challenge (Figure 1) [34, 35]. Clinical studies can be designed to determine whether the induction of anti-M2 Abs prevents disease in humans. If so, efforts can be undertaken to evaluate whether a more robust and protective anti-M2 Ab response can be achieved by immunization than by repeated natural infection in nature. Presentation of the M2 protein to the immune system in a more immunogenic form via vaccina­ tion than occurs in natural infection may be important in this regard. In conclusion, two approaches to the development of vaccines for pandemic preparedness can be exploited. The first and more immediately accessible uses existing technology to generate vaccines that induce highly functional and pro­ tective Abs. Efforts in this area should focus on pre-emptive preparation of vaccine seed viruses and evaluation of their safety and immunogenicity. Strategies to augment Ab responses with adjuvants and dose sparing immunization regimens are also being explored. The second approach will build on basic research to explore possibilities to induce cross- protective cell-mediated immunity or Ab to conserved epitopes such as those on the HA or M2 proteins but this has a longer lag time than the first approach.

Acknowledgement: The authors would like to thank Nancy Touchette for helpful discussions and review of the manuscript.

THE IMMUNOLOGY OF INFLUENZA INFECTION 15 References primed human population, Vaccine against infection with A/Vietnam/1203/04 1. World Health Organization (WHO): Avian 2003b;21:1687-1693. (H5N1) virus in ferrets, J Inf Diseases Influenza. Available at 17. Stephenson I et al., Phase I evaluation of 2006;194:1040-1043. http://www.who.int/csr/disease/avian_influenz intranasal trivalent inactivated influenza vac­ 32. Goji NA et al., Immune responses of healthy a/en/index.html. cine with nontoxigenic Escherichia coli entero­ subjects to a single dose of intramuscular 2. Thompson WW et al., Mortality associated toxin and novel biovector as mucosal inactivated influenza A/Vietnam/1203/2004 with influenza and respiratory syncytial virus adjuvants, using adult volunteers, J Virol (H5N1) vaccine after priming with an anti­ in the United States, JAMA 2003;289:179-186. 2006;80:4962-4970. genic variant. Abstract presented at IDSA 3. Wright PF and Webster RG, “Orthomyxoviruses,” 18. Treanor JJ et al., Safety and immunogenicity meeting, Toronto, Ontario, Canada, October in Fields Virology, DM Knipe, et al., Editors. of an inactivated subvirion influenza A (H5N1) 9, 2006. 2001, Lippincott Williams and Wilkens: vaccine, N Engl J Med 2006;354:1343-1351. 33. Russell RJ et al., H1 and H7 influenza Philadelphia. p. 1533-1580. 19. Luke CJ et al., Vaccines for Pandemic haemagglutinin structures extend a structural 4. Crawford PC et al., Transmission of equine Influenza, Emerg Infect Dis 2006;12:66-72. classification of haemagglutinin subtypes, influenza virus to dogs, Science 2005; 20. Suguitan AS et al., Live, attenuated influenza A Virology 2004;325:287-296. 310:482-485. H5N1 candidate vaccines provide broad cross- 34. Neirynck S et al., A universal influenza A vac­ 5. Webster RG et al., Evolution and ecology protection in mice and ferrets, PLoS Med cine based on the extracellular domain of the of influenza A viruses, Microbiol Rev 2006;3:1541-1555. M2 protein, Nat Med 1999;5:1157-1163. 1992;56:152-179. 21. Bright RA et al., Impact of glycosylation on 35. Treanor JJ et al., Passively transferred mono­ 6. Wilson IA et al., Structural basis of immune the immunogenicity of a DNA-based clonal Ab to the M2 protein inhibits influenza recognition of influenza virus hemagglutinin, influenza H5 HA vaccine, Virology A virus replication in mice, J Virol Annu Rev Immunol 1990;8:737-771. 2003;308:270-278. 1990;64:1375-1377. 7. Murphy BR et al., “Immunization against viral 22. Epstein SL et al., DNA vaccine expressing 36. Subbarao K et al., Development of effective diseases,” in Fields Virology, DM Knipe, et al., conserved influenza virus proteins protective vaccines against pandemic influenza, Editors. 2001, Lippincott Williams & Wilkins: against H5N1 challenge infection in mice, Immunity 2006;24:5-9. Philadelphia. p. 435-468. Emerg Infect Dis 2002;8:796-801. 8. Epstein SL, Prior H1N1 influenza infection 23. Kodihalli S et al., Strategies for inducing and susceptibility of Cleveland Family Study protection against avian influenza A virus participants during the H2N2 pandemic of subtypes with DNA vaccines, Vaccine 1957: an experiment of nature, J Inf Dis 2000;18:2592-2599. 2006;193:49-53. 24. Qiu M et al., Protection against avian 9. Fitch WM et al., Long term trends in the evo­ influenza H9N2 virus challenge by immuniza­ lution of H(3) HA1 human influenza type A, tion with hemagglutinin- or neuraminidase- Proc Natl Acad Sci USA 1997;94:7712-7718. expressing DNA in BALB/c mice, Biochem 10. Atmar RL et al., Safety and immunogenicity of Biophys Res Commun 2006;342:1124-1131. nonadjuvanted and MF59-adjuvanted 25. Epstein SL et al., Protection against multiple influenza A/H9N2 vaccine preparations, Clin influenza A subtypes by vaccination with Infect Dis 2006;43:1135-1142. highly conserved nucleoprotein, Vaccine 11. Bresson J-L et al., Safety and immunogenicity 2005;23:5404-5410. of an inactivated split-virion influenza 26. Gao W et al., Protection of mice and poultry A/Vietnam/1194/2004 (H5N1) vaccine: phase from lethal H5N1 avian influenza virus I randomized trial, Lancet 2006;367:1657­ through adenovirus-based immunization, J 1664. Virol 2006;80:1959-1964. 12. Hehme N et al., Pandemic preparedness: les­ 27. Hoelscher MA et al., Development of adenovi­ sons learnt from H2N2 and H9N2 candidate ral-vector-based pandemic influenza vaccine vaccines, Med Microbiol Immunol (Berl) against antigenically distinct human H5N1 2002;191:203-208. strains in mice, Lancet 2006;367:475-481. 13. Lin J et al., Safety and immunogenicity of an 28. Kong WP et al., Protective immunity of lethal inactivated adjuvanted whole-virion influenza challenge of the 1918 pandemic influenza A (H5N1) vaccine: a phase I randomized con­ virus by vaccination, Proc Natl Acad Sci USA trolled trial, Lancet 2006;368:991-997. 2006;103:15987-15991. 14. Nicholson KG et al., Safety and antigenicity of 29. Kistner O et al., Development of a safe and non-adjuvanted and MF59-adjuvanted immunogenic mammalian cell (Vero) derived influenza A/Duck/Singapore/97 (H5N3) vac­ inactivated H5N1 whole virus candidate vac­ cine: a randomised trial of two potential vac­ cine using the H5N1 wild type human isolate cines against H5N1 influenza, Lancet A/Viet Nam/1203/2004. Abstract presented at 2001;357:1937-1943. Influenza Vaccines for the World Conference, 15. Stephenson I et al., Safety and antigenicity of Vienna, Austria, October 19, 2006. whole virus and subunit influenza A/Hong 30. Govorkova EA et al., Immunization with Kong/1073/99 (H9N2) vaccine in healthy reverse-genetics-produced H5N1 influenza adults: phase I randomised trial, Lancet vaccine protects ferrets against homologous 2003a;362:1959-1966. and heterologous challenge, J Inf Diseases 16. Stephenson I et al., Boosting immunity to 2006;194:143-145. influenza H5N1 with MF-59-adjuvanted 31. Lipatov AS et al., Cross-protectiveness and H5N3 A/Duck/Singapore/97 vaccine in a immunogenicity of influenza A/Duck/Singapore/3/97 (H5N3) vaccines

16 THE JORDAN REPORT 2007 Figure 1

Figure Legends Figure 1. Life cycle of influenza virus and role of the adaptive immune response during infection. Influenza virus attaches to the epithelial cell sur­ face through binding of the viral hemagglutinin (HA) protein to cell surface sialic acid receptors (1, 2). The virion is internalized through endocytosis and fusion (3). Opening of the M2 channel allows proton flow across the viral membrane (4), triggering release of viral genes into the cytoplasm from where they travel to the nucleus. Viral proteins produced in cytoplasm assemble with viral genes and bud from the cell membrane as progeny virions (5). Release of new virus particles (6) requires the viral neuraminidase (NA) protein, which cleaves sialic acid receptors from the cell membrane. Antibodies (Abs) to the HA protein block virus attachment (inset, upper left), thereby decreasing the number of cells infected. They can also function to prevent fusion (4). Abs to the NA protein (inset, upper right) bind virus to the cell, preventing release of new virions. Abs to the M2 protein bind virus to the cell and prevent release of viral particles into the extracellular fluid (inset, lower left). Cell-mediated immunity contributes to resistance when CD8+ T cells specific for viral proteins such as nucleoprotein (NP) or polymerase proteins (PB2 and PA) recognize viral peptides presented by major histocompatibility complex (MHC) class I proteins, resulting in the release of cytokines with antiviral activity (IFN-γ and TNF-α) and perforins that mediate cytolysis of the infected cell. Lysis of the infected cell decreases the amount of virus released by the cell. The latter three mechanisms, NA Abs, M2 Abs, and CD8+ T cells, operate after a cell becomes infected. Only HA Abs prevent infection; this is likely why they are the most effec­ tive in vivo.

THE IMMUNOLOGY OF INFLUENZA INFECTION 17 Figure 2

Figure 2. Course of immune response during influenza infection. Influenza virus titers peak at approximately three days post-infection, at which time antibodies (Abs) and T-cell responses begin to appear. Activated T-cell responses peak on days six to nine during the primary infection and then sub­ side into a memory or resting state, whereas serum and mucosal Ab levels are sustained. Abs present at the time of reinfection result in lower viral titers and a reduction in symptoms. (Upper respiratory infection, URI; lower respiratory infection, LRI.)

18 THE JORDAN REPORT 2007 Kanta Brian Anthony S. Subbarao, Murphy, Fauci, M.D. M.D., M.D. Since 1984, Dr. M.P.H. Dr. Murphy Fauci has been Dr. Subbarao received his B.A. Director of the received her degree from the National M.B., B.S., Wesleyan Institute of in 1982 from University, Allergy and the Christian Connecticut in Infectious Medical College, Vellore, University of 1964 and his M.D. degree from the Diseases (NIAID) of the National Madras, India, and completed a residency University of Rochester School of Institutes of Health (NIH). He also is in pediatrics at Cardinal Glennon Medicine in 1969. After an internship in Chief of the Laboratory of Memorial Hospital for Children, St. Louis medicine at Stanford University he came Immunoregulation at NIAID. Dr. Fauci University. She completed a fellowship to the Laboratory of Infectious Diseases has made many contributions to basic in pediatric infectious diseases and (LID), NIAID in 1970. He became Head and clinical research on the pathogenesis earned an MPH in epidemiology from of the Respiratory Viruses Section of LID and treatment of immune-mediated the University of Oklahoma Health in 1983 and Co-Chief of LID in 2001, a diseases. He has pioneered the field of Sciences Center. After postdoctoral position he holds today along with Dr. human immunoregulation, making a training in the Laboratory of Infectious Robert Purcell. number of scientific observations that Diseases (LID), NIAID, she was on faculty His research on the live attenuated serve as the basis for current under­ at McGill University, Montreal, Canada, influenza virus vaccine from 1975 to 1995 standing of the regulation of the human and subsequently served as Chief of the led to the licensure of the live attenuated immune response. Dr. Fauci has made Molecular Genetics Section of the trivalent influenza virus vaccine (FluMist) seminal contributions to the under­ Influenza Branch at the Centers for Disease by MedImmune in 2003. He also partici­ standing of how the acquired immuno­ Control and Prevention in Atlanta, pated in the development of the first deficiency syndrome (AIDS) virus Georgia. Dr. Subbarao joined the LID as monoclonal antibody to prevent/treat an destroys the body’s defenses. a Senior Investigator in 2002. Her research infectious disease—the monoclonal At major medical centers through­ is focused on the development of vaccines antibody called Synagis‚ that is used to out the country, Dr. Fauci has served as against pandemic strains of influenza prevent disease caused by respiratory Visiting Professor. He has lectured and the development of animal models syncytial virus infection in infants with throughout the world and is the recipient and evaluation of vaccines against the compromised cardiopulmonary function. of numerous awards. severe acute respiratory syndrome In 1985, Dr. Peter Collins joined LID, and Dr. Fauci is a member of the (SARS) coronavirus. he and Dr. Murphy have been working National Academy of Sciences; Royal collaboratively to develop live attenuated Danish Academy of Science and Letters; virus vaccines to prevent hospitalizations American College of Physicians; American caused by a set of six respiratory viruses: Society for Clinical Investigation; two subgroups of RSV, three parainfluenza Infectious Diseases Society of America; viruses, and the newly discovered human American Academy of Allergy, Asthma metapneumovirus. He has recently been and Immunology; and other professional involved with the development of vaccines societies. He serves on many editorial for six flaviviruses that are major causes boards and is author, coauthor, or editor of disease in humans: the four dengue of more than 1,000 scientific publications. viruses, West Nile Virus, and tickborne encephalitis virus. Vaccines for three other viruses causing encephalitis are also under development.

THE IMMUNOLOGY OF INFLUENZA INFECTION 19 20 THE JORDAN REPORT 2007 Vaccine Production and Supply Vulnerabilities in the Present System

Walter A. Orenstein, M.D., Alan R. Between November 2000 and August 2006, doses. In the case of influenza, there were Hinman, M.D., M.P.H., Lance E. there have been shortages of vaccines marked decreases in routine immuniza­ Rodewald, M.D. against 10 diseases: diphtheria, influenza, tion coverage among some population measles, mumps, pertussis, pneumococcal groups for whom the vaccine was usually ew measures compare with the disease, rubella, tetanus, varicella, and recommended [14]. public health impact of vaccines. meningococcal disease [10-13]. A major reason for the tenuous status F During the past century, smallpox Supplies have been inadequate at some of the vaccine supply is the limited has been eradicated worldwide, polio times during this period for tetanus and number of manufacturers for any indi­ has been eliminated in most countries of diphtheria toxoids (Td); diphtheria and vidual product. As of August 2006, there the world, and measles and rubella are tetanus toxoids and acellular pertussis were only single licensed manufacturers no longer endemic in the United States vaccine (DTaP); pneumococcal conjugate for vaccines against measles, mumps, [1]. In an evaluation by the Partnership vaccine (PCV7); measles, mumps, rubella rubella, varicella, pneumococcal disease for Prevention of 30 clinical preventive (MMR) vaccine; varicella vaccine; (PCV7), polio (as a single vaccine), services widely recommended by the U.S. influenza vaccine; and meningococcal meningococcal disease (meningococcal Preventive Services Task Force, childhood conjugate vaccine. Table 1 shows shortages conjugate vaccine, MCV4), rotavirus, immunization received a perfect score, in childhood vaccines between 2000­ human papillomavirus vaccine, zoster based on clinically preventable burden 2006 [10]. The causes of the shortages vaccine, and influenza (for children less and cost-effectiveness [2]. New vaccines include manufacturers’ unexpected than four years of age). In addition, continue to be developed and introduced departures from the market, long time most other vaccines in the routine child for widespread use. During the last frames for remaining manufacturers to and adolescent schedule have only two decade alone, the Advisory Committee gear up production to meet the shortfalls, manufacturers, including vaccines against on Immunization Practices (ACIP) has production problems, failure to keep up hepatitis B, hepatitis A, diphtheria, tetanus, recommended that all children be pro­ with requirements for current Good and pertussis. However, having multiple tected against six more diseases (varicella, Manufacturing Practices (cGMP), plant manufacturers does not assure shortages pneumococcal disease, influenza, hepatitis shutdowns to make renovations, and will be prevented. Vaccines with multiple A, meningococcal disease, and rotavirus) inadequate reserves to cover short-term manufacturers can have shortages because [3-8]. Human papillomavirus vaccine supply disruptions. In addition, there the manufacturers seldom have large was recently recommended for all 11- were unanticipated consequences of the inventories or unused capacity that can to 12-year-old girls [9]. More new decision to remove the ethyl-mercury be rapidly brought online to mitigate an vaccines are close to final development containing preservative, thimerosal, from unanticipated shortfall. There is very and licensure. Translating vaccine vaccines as a precautionary measure to little surge manufacturing capacity development successes into disease reduce overall exposure to mercury. because redundant capacity is costly. reductions, however, rests on a fragile Removing the preservative required Academia, funded primarily by the base of vaccine suppliers [10]. switching from multiple dose to single National Institutes of Health (NIH), and Supply vulnerabilities have been high­ dose packaging of DTaP vaccine, which many small firms have played major roles lighted by an unprecedented number of reduced the number of doses produced in vaccine discovery and early development vaccine shortages since 2000. While there by one manufacturer. [1]. However, few manufacturers have is not a single reason for these problems, In a number of instances, the shortages been able to bring a vaccine through late as a whole they underscore the need to led to transient changes in the routine stages of development, clinical testing, improve the vaccine supply system. immunization schedule to defer or drop submitting the required documentation

VACCINE PRODUCTION AND SUPPLY 21 for licensure, and establishing the produc­ influenza vaccine and one manufacturer [20, 21]. These stockpiles really represent tion capacity to supply multiple cohorts of live attenuated vaccines. storage and rotation contracts under of children with vaccine produced under The National Vaccine Advisory which new vaccines go into a “bubble cGMP. The costs of vaccine development Committee (NVAC) has reviewed the inventory,” and older vaccines are rotated have been estimated to range generally vaccine supply situation in the United out so released products have a reasonable from $300 million to $800 million [15]. States and has made a number of rec­ shelf life. These reserves can provide Costs for development of live attenuated ommendations to try to avoid future security against short-term supply disrup­ influenza vaccine may have exceeded $1 shortages [11, 12, 18, 19]. These include tions but may not be adequate to solve billion [16]. Few private firms are willing (1) developing financial incentives, (2) major problems such as sole producers or able to make those kinds of financial simplifying the regulatory process, (3) leaving the market. Improvements in commitments. developing or enhancing vaccine stock­ vaccines, such as combination vaccines, Vaccine supply would be more secure piles, (4) addressing liability issues, and challenge the logistics of stockpiling if there were multiple manufacturers of (5) enhancing communication and strategies because a new vaccine may each vaccine. However, with the notable collaboration among key stakeholders. make a stockpiled vaccine obsolete. exception of influenza vaccines, there Financial incentives are needed to Nevertheless, the stockpiles have been seems to be little interest in challenging encourage manufacturers to invest in invaluable and have been used to minimize manufacturers of current vaccines with research and development as well as adverse consequences of supply problems comparable products not yet licensed in continuing upgrades of their facilities on at least 12 occasions since 1984. this country. This may reflect the hesitancy for currently licensed vaccines to meet The National Vaccine Injury Com­ of other global manufacturers to go evolving good manufacturing practices. pensation Program (VICP) has played a through the expensive process of receiving Such incentives may include setting critical role in providing compensation U.S. Food and Drug Administration (FDA) pricing compatible with reasonable for persons injured by vaccines and for approval only to compete to receive a profits, covering the costs of developing decreasing manufacturer and provider share of a market defined for the most products, offering tax incentives for liability for injuries that occur despite part by the birth cohort (approximately constructing new facilities or upgrading production of vaccines in compliance four million each year) and the limited others, and providing rewards for com­ with all federal regulations and use number of doses needed in the immuniza­ panies that consistently meet federal and according to existing recommendations. tion schedule (one to five, depending on other contract requirements. At the Nonetheless, concerns have been raised the vaccine). Some economists have moment, multinational vaccine producers regarding a resurgence of litigation that, stated that the current U.S. market must meet a host of different regulatory at a later point, could cause some com­ would be unable to sustain more than requirements depending upon the coun­ panies to leave the market or decrease the one or two manufacturers for a given tries for which they seek licensure. incentives for new manufacturers to enter vaccine, which is why so few “me-too” Harmonization of requirements could it [22]. Strengthening and expanding the products are introduced [17]. In contrast, make it easier to get vaccines approved VICP would help to safeguard the vaccine there may be substantially more interest in multiple countries, which could lead supply and benefit all parties—manufac­ in the influenza market because current to considerable cost savings. turers, providers, and consumers. recommendations call for annual vacci­ The NVAC also called for review of Finally, the NVAC urged greater nation of approximately 218 million existing cGMP requirements to assure communication between industry and Americans and the largest use of vaccines they are science-based, potentially elimi­ vaccine end users, including the CDC, to date has been 83 million doses [8]. nate or modify those that are not, and so actions could be taken more quickly Thus, there is substantial potential to allow for flexibility as long as it does not should supply problems occur. In addition, increase the size of the market. During compromise the safety and efficacy of it felt the need for an educational cam­ 2005, an additional producer was licensed the vaccines. The Centers for Disease paign to emphasize the safety and effec­ in the United States and another producer Control and Prevention (CDC) has tiveness of vaccines and their important from Canada is attempting to enter the financial authority, through the Vaccines contributions to health. U.S. market. As of August 2006, there are for Children (VFC) program, to establish three licensed manufacturers of inactivated six-month stockpiles of childhood vaccines

22 THE JORDAN REPORT 2007 Table 1. Childhood Vaccine Shortages 2000-2006

Vaccine Approximate dates Immediate precipitating factors

Td 11/2000–6/2002 Decreased production in 2000 by both major U.S manufacturers (Wyeth, Aventis Pasteur)

Decision of one manufacturer (Wyeth) to cease production

11-month period required for production led to a lag before increased supplies became available from remaining major manufacturer

DTaP 3/2001–7/2002 Recommendation to eliminate/decrease use of thimerosal-containing vaccines

Decision of one manufacturer (Wyeth) to cease production

PCV 9/2001–5/2003 Unanticipated initial demand

Several sporadic manufacturing problems at the sole manufacturer (Wyeth)

MMR 10/2001–7/2002 Voluntary renovations at a vaccine filling suite that affected multiple vaccines (Merck)

Varicella 10/2001–8/2002 Voluntary renovations at a vaccine filling suite that affected multiple vaccines (Merck)

MCV4 5/2006–present Demand for vaccine greater than anticipated and exceeded manufacturer’s capacity

Influenza 10/2004–4/2005 One of two manufacturers (Chiron) dropped out because of bacterial contamination

Abbreviations: Td-tetanus and diphtheria toxoids, adult; DTaP-diphtheria and tetanus toxoids and pertussis vaccines, adsorbed; PCV-pneumococcal conjugate vaccine; MMR-measles, mumps, and rubella vaccine; MCV4—meningococcal conjugate vaccine. Table adapted and reprinted with permission from the Annual Review of Public Health, Volume 27 (c) 2006 by Annual Reviews, www.annualreviews.org.

VACCINE PRODUCTION AND SUPPLY 23 References 14. Centers for Disease Control and Prevention, 1. Orenstein WA et al., Immunizations in the Experiences with obtaining influenza vaccina­ United States: success, structure, and stress, tion among persons in priority groups during Health Aff (Millwood) 2005;24(3):599-610. a vaccine shortage-United States, October- 2. Maciosek MV et al., Priorities among effective November, 2004, MMWR Morb Mortal Wkly clinical preventive services: results of a system­ Rep 2004;53(49):1153-1155. atic review and analysis, Am J Prev Med 15. Plotkin SA, Why certain vaccines have been 2006;31(1):52-61. delayed or not developed at all, Health Aff 3. Centers for Disease Control and Prevention, (Millwood) 2005;24(3):631-634. Prevention of varicella, recommendations of 16. Poland GA and Marcuse EK, Vaccine availabil­ the Advisory Committee on Immunization ity in the US: problems and solutions, Nat Practices (ACIP), MMWR Recomm Rep Immunol 2004;5(12):1195-1198. 1996;45(RR-11):1-36. 17. Danzon P and Pereira NS, Why sole-supplier 4. Centers for Disease Control and Prevention, vaccine markets may be here to stay, Health Preventing pneumococcal disease among Aff (Millwood) 2005;24(3):694-696. infants and young children, recommendations 18. Klein JO and Helms CM, Strengthening the of the Advisory Committee on Immunization supply of routinely administered vaccines in Practices (ACIP), MMWR Recomm Rep the United States: progress and problems­ 2000;49(RR-9):1-35. 2005; Clin Infect Dis 2006;42 Suppl 3:S145­ 5. Bilukha OO and Rosenstein N, Prevention 150. and control of meningococcal disease, recom­ 19. Klein JO and Myers MG, Strengthening the mendations of the Advisory Committee on supply of routinely administered vaccines in Immunization Practices (ACIP), MMWR the United States: problems and proposed Recomm Rep 2005;54(RR-7):1-21. solutions, Clin Infect Dis 2006;42 Suppl 3:S97­ 6. Parashar UD et al., Prevention of rotavirus 103. gastroenteritis among infants and children, 20. Lane KS et al., The United States pediatric provisional ACIP recommendations for use of vaccine stockpile program, Clin Infect Dis rotavirus vaccine (RV), MMWR Recomm Rep 2006;42 Suppl 3:S125-129. 2006;55(RR-12);1-13. 21. Rodewald LE et al., Vaccine supply problems: 7. Fiore AE et al., Prevention of hepatitis A a perspective of the Centers for Disease through active or passive immunization, rec­ Control and Prevention, Clin Infect Dis ommendations of the Advisory Committee on 2006;42 Suppl 3:S104-110. Immunization Practices (ACIP), MMWR 22. Evans G, Update on vaccine liability in the Recomm Rep 2006;55(RR-7):1-23. United States: presentation at the National 8. Smith NM et al., Prevention and control of Vaccine Program Office Workshop on influenza, recommendations of the Advisory strengthening the supply of routinely recom­ Committee on Immunization Practices mended vaccines in the United States, 12 (ACIP), MMWR Recomm Rep 2006;55(RR­ February 2002, Clin Infect Dis 2006;42 Suppl 10):1-42. 3:S130-137. 9. Centers for Disease Control and Prevention. http://www.cdc.gov/­ od/oc/media/pressrel/r060629.htm. Accessed 8/2/2006. 10. Hinman AR et al., Vaccine shortages: history, impact, and prospects for the future, Annu Rev Public Health 2006;27:235-259. 11. Klein JO and Myers MG, Vaccine shortages: why they occur and what needs to be done to strengthen vaccine supply, Pediatrics 2006;117(6):2269-2275. 12. Santoli JM et al., Strengthening the supply of routinely recommended vaccines in the United States: recommendations from the National Vaccine Advisory Committee, JAMA 2003;290(23):3122-3128. 13. Centers for Disease Control and Prevention, Notice to readers: Limited supply of meningo­ coccal conjugate vaccine, recommendation to defer vaccination of persons aged 11-12 Years, MMWR Morb Mortal Wkly Rep 2006;55(20):567-568.

24 THE JORDAN REPORT 2007 Walter A. Alan R. Lance E. Orenstein, Hinman, Rodewald, M.D. M.D., M.P.H. M.D. Dr. Orenstein Dr. Hinman is Dr. Rodewald is joined the Emory a Senior Public Director of the University School Health Scientist Immunization of Medicine in at The Task Force Services Division March 2004 as for Child Survival (ISD) in the Director of the and Development, a program affiliated National Center for Immunization and Emory Program for Vaccine Policy and with Emory University and The Carter Respiratory Diseases of the CDC. The ISD Development, and as Associate Director Center. At the Task Force, he works with division administers the Vaccines for of the Emory Vaccine Center. Dr. Oren- the Public Health Informatics Institute, a Children program and the Section 317 stein is the former Director of the Robert Wood Johnson Foundation- immunization grants program to state National Immunization Program at the funded program seeking to foster devel­ and urban area health departments; con­ Centers for Disease Control and Preven­ opment of integrated preventive health ducts health services research to improve tion (CDC) and former Assistant Sur­ information systems. In addition, he delivery of vaccines; provides training geon General of the U.S. Public Health works with the PARTNERS TB Control and education to health professionals; Service. During his 26-year career at Program, a program funded by the Bill evaluates effectiveness of program CDC he led a $1.6 billion effort with & Melinda Gates Foundation addressing implementation through the National more than 450 staff dedicated to reduc­ multidrug-resistant tuberculosis in Peru Immunization Survey; and provides ing vaccine-preventable disease burdens and globally. technical support and funding for around the world, including elimination Since 1965 he has been involved in immunization information systems. of some of the greatest causes of child­ public health programs at state, national, Dr. Rodewald received his medical hood mortality and disability. He served and international levels, primarily work­ degree from Southern Illinois University as the CDC liaison member to the ing with the Centers for Disease Control School of Medicine and trained in pedi­ National Vaccine Advisory Committee and Prevention. In addition, he has worked atrics at the University of Virginia and and the American Academy of Pediatrics for the state health departments of New the Robert Wood Johnson School of Committee on Infectious Diseases, having York and Tennessee. He retired from the Medicine and Dentistry. He had three-year played a major role in developing critical U.S. Public Health Service in July 1996, NIH fellowship training in medical infor­ immunization policy documents. Dr. having attained the rank of Assistant matics at the University of Illinois where Orenstein has been a member of the Surgeon General. Dr. Hinman is the he received an M.S. in computer science, External Advisory Board of the HIV author or co-author of more than 300 and two-year health services research Vaccine Trials Network. He is Director scientific publications. He is an Adjunct training at the University of Rochester for Strategic Planning of the Hope Clinic, Professor at the Rollins School of Public School of Medicine and Dentistry in the site of a number of HIV vaccine trials. Health of Emory University in the Robert Wood Johnson General Academic Along with Dr. Stanley Plotkin, Dr. Oren- Departments of Epidemiology and Pediatrics Training Program. stein co-edited Vaccines, 4th edition, a Global Health. At the University of Rochester he 1,600-page volume with more than 125 was Associate Professor of Pediatrics and contributors that is the leading textbook Emergency Medicine and Director of the in the field. Pediatric Emergency Department. In 1996, he joined the CDC as Associate Director for Science in the ISD. His research inter­ ests include structure of the immunization delivery system, and methods to improve immunization coverage and to integrate immunizations into primary care more completely and seamlessly.

VACCINE PRODUCTION AND SUPPLY 25 26 THE JORDAN REPORT 2007 Project BioShield A Tool for Developing, Using, and Stockpiling Needed Public Health Emergency Medical Countermeasures

Noreen A. Hynes, M.D., M.P.H. and simplify the solicitation, review, following interagency and White House and award of grants and contracts for approval. Within the HHS, the Office Introduction the development of critical medical of the Assistant Secretary for Prepared­ he development and availability of countermeasures. ness and Response has procurement medical countermeasures against authority for Project BioShield acqui­ T chemical, biological, radiological, ● Facilitating Medical Countermeasure sitions using this Special Reserve Fund. and nuclear (CBRN) threats are key Use in Emergencies: Project BioShield components of President George W. establishes the Emergency Use Autho­ Project BioShield: Prioritizing Bush’s biodefense strategy, as outlined rization (EUA) to provide access to the Government Investments in the National Strategy to Combat best available medical countermeasures The three critical elements of Project Weapons of Mass Destruction [1], following a Declaration of Emergency BioShield aim to seamlessly integrate Biodefense for the 21st Century [2], and by the Secretary of the Department of medical countermeasure acquisitions with the National Strategy for Medical Health and Human Services (HHS). overall U.S. Government preparedness Countermeasures against Weapons of The Declaration could be based on and emergency response plans. Under Mass Destruction [3]. On July 21, 2004, either the Secretary’s determination of Project BioShield, the U.S. Government the President signed Public Law (P.L.) a public health emergency with the seeks to make balanced acquisitions of 102-276, the Project BioShield Act of significant potential to affect national the most urgently needed medical counter­ 2004 (Project BioShield), as part of the security, or on a heightened risk of a measures, within the limits of the Special broader strategy to defend America CBRN attack on the public or U.S. Reserve Fund (See Table 1 for 2004-2006 against the threat of weapons of mass military forces (as determined by the acquisitions). This provides the “pull” destruction [4]. The purpose of Project Secretary of the Department of Home­ that complements the “push” in medical BioShield is to accelerate the research, land Security (DHS) or the Secretary countermeasure development provided by development, purchase, and availability of Defense, respectively). separate funding mechanisms for discov­ of effective medical countermeasures ery, research, and development provided against CBRN agents. ● Funding of Needed Countermeasures: to the NIH (Figure 1). In support of this Project BioShield institutes a secure goal, a U.S. Government science-informed, Project BioShield: Three funding source for the purchase of policy-guided, interagency process, under Critical Elements critical medical countermeasures, the auspices of the Executive Office of the Project BioShield includes three including vaccines, biologics, therapeu­ President, is responsible for developing approaches to reaching the goal of having tics, and diagnostics. The legislation and coordinating research agendas safe, effective, and deployable medical authorizes the use of $5.6 billion in focused on medical countermeasures; countermeasures to respond to the effects funding over 10 years for the advanced prioritizing the development and acqui­ of CBRN threats on the U.S. population. development and purchase of priority sition of new medical countermeasures ● Facilitating Research and Development: medical countermeasures. This “Special across Federal agencies, including under Project BioShield grants the National Reserve Fund” was provided in the Project BioShield; and ensuring the exis­ Institutes of Health (NIH)/National Fiscal Year (FY) 2004 DHS Appropria­ tence of a product development pipeline Institute of Allergy and Infectious tions Act [3] and becomes available to for needed countermeasures. Diseases (NIAID) authorities to expedite the Secretary of HHS for procurements

PROJECT BIOSHIELD 27 Specific statutory requirements must Project BioShield Targeted drug is between $800 million and $1.7 be fulfilled prior to proceeding with any Medical Countermeasures: billion [7]. The Special Reserve Fund for Project BioShield procurement (Figure 2). Successes and Challenges of Project BioShield holds $5.6 billion to First, the Secretary of DHS determines the First Two Years be expended over 10 years. This amount that a particular biological, chemical, Implementation Successes has not drawn the attention of large radiological, or nuclear agent poses a The first two years of Project BioShield pharmaceutical or biotechnology firms “material threat” to the population of implementation have been guided by the to date, possibly because the potential the United States. Second, the Secretary interagency strategy defined in December payoff for a breakthrough in medical of HHS determines if additional medical 2003 and supported by Department of countermeasures against CBRN threats countermeasures are required. Third, the Homeland Security Material Threat is modest when compared with other Secretary of the HHS assesses both fully Determinations (MTD) for anthrax, drugs. For example, the global market developed and commercially available smallpox, botulinum toxins, and radio­ for a major cholesterol-lowering agent medical countermeasures as well as logical and nuclear agents. Procurement was $10.3 billion in 2003 and exceeded countermeasures in late-stage advanced programs now exist for vaccines to the global market for all vaccines that development, to determine if they are counter anthrax and smallpox, biologics year [8]. Despite a global vaccine market appropriate for acquisition, using the therapies directed against anthrax and that is continuing to expand annually at Special Reserve Fund, and for inclusion botulinum toxins, and therapeutic agents a 10 to 12 percent growth rate, the in the Strategic National Stockpile. A to treat internalized particulate radiation annual global market for vaccines is non-commercially available product and acute radiation syndrome secondary expected to be only $17 billion in 2010 [9]. must be within eight years of licensure, to near-total or total body irradiation Smaller companies, however, have approval, or clearance by the U.S. Food (For more information, visit been attracted to participate in Project and Drug Administration at the time of www.hhs.gov/aspr/ophemc/bioshield/ BioShield. Successful participation by contract award. From an operational procurement_activities/PBSPrcrtPrjct/in these manufacturers should result in an standpoint, this means that product dex.html). The nature of the CBRN expansion of nationally available phar­ manufacturers must provide sufficient threat is such that the regulatory pathway maceutical manufacturing capacity and data to demonstrate that there are no for most new products includes use of expertise. A cost of building this capacity major barriers to approval or licensure the so-called “Animal Rule,” in cases among smaller, less experienced compa­ of their product. These data may include, where human efficacy trials would be nies is that more intensive technical but are not limited to, Phase I clinical unethical [4, 5]. Animal models needed assistance and oversight to meet the trial results, toxicology study results, to regulate these products often have requirements of Project BioShield pro­ pharmacokinetics or immunogenicity been undefined at the outset of product curement contracts and mitigate the risk data, animal efficacy studies, and development and occur concurrently along of failure is necessary [12]. demonstrations of current Good with that development. Pyridostigmine As noted previously, for a counter­ Manufacturing Practices. Fourth, the bromide, a pretreatment against the measure to be eligible for Project Secretaries of DHS and HHS jointly rec­ effects of the nerve agent soman, is the BioShield, solid clinical experience ommend purchase of the medical coun­ first drug to be approved using the and/or research data must support “a termeasure to the Director of the Office Animal Rule [6]. reasonable conclusion that the counter­ of Management and Budget (OMB). measure will qualify for [FDA] approval The OMB Director, under delegated Implementation Challenges or licensure within eight years after the authority from the President, approves The experience implementing Project date of a determination [4].” Late-stage the purchase of medical countermeasures BioShield over the first two years since research and development funds, apart as recommended by the Secretaries of enactment has highlighted a number of from the Special Reserve Fund, to support DHS and HHS. issues that make acquisitions challenging potential candidates before they are eligible and unique. for Project BioShield are critical to It is estimated that the cost of devel­ ensuring full medical countermeasure oping and bringing to market a new maturation. To address this, HHS has

28 THE JORDAN REPORT 2007 proposed $169 million for advanced development in the FY08 budget to support promising candidates. Funding advanced development to levels that support multiple candidates is key to mitigating risk in the Project BioShield acquisition phase of the product development pathway. The Pandemic and All-Hazards Preparedness Act estab­ lished the Biomedical Advanced Research and Development Authority (BARDA) [13]. Through BARDA, HHS will promote innovation, reduce risk to both medical countermeasure developers and the Government, and invest in medical countermeasure advanced development in order to bring candidate products to an acquisition-ready stage. HHS anticipates that available funding through these authorities will support the highest prior­ ity medical countermeasure development programs. Finally, although liability issues have not prevented the completion of any countermeasure acquisitions to date, liability protection remains a major source of concern to the biotechnology and pharmaceutical industries. This has been a recurring concern in the Project BioShield acquisition process. In 2005, Congress passed the “Public Readiness and Emergency Preparedness (PREP) Act” as part of the 2006 Defense Appropriations Act (P.L. 109-148). This legislation included liability protections for manu­ facturers of security and pandemic countermeasures.

PROJECT BIOSHIELD 29 References 1. The White House, National Strategy to Combat Weapons of Mass Destruction, December 2002 www.whitehouse.gov/news/releases/2002/12/ WMDStrategy.pdf. 2. The White House, Biodefense for the 21st Century, April 28, 2004 www.whitehouse.gov/homeland/20040430.ht ml (July 1, 2006). 3. National Strategy for Medical Countermeasures against Weapons of Mass Destruction, February 2007. www.whitehouse.gov/news/releases/2007/02/ 20070207-2.html 4. Project BioShield Act of 2004, July 21, 2004, S.15 (July 1, 2006). 5. Department of Homeland Security Appropriations Act, 2004, H.R. 2555, October 1, 2004 (July 1, 2006). 6. New Drug and Biological Drug Products; Evidence Needed to Demonstrate Effectiveness of New Drugs When Human Efficacy Studies Are Not Ethical or Feasible, Final Rule. 67 Fed. Reg. 37988-37998 (May 31, 2002). Codified at 21 C.F.R. Parts 314 and 601. 7. Committee on Animal Models for Testing Interventions Against Aerosolized Bioterrorism Agents. Overcoming Challenges to Develop Countermeasures Against Aerosolized Bioterrorism Agents: Appropriate Use of Animal Models, 2006, National Academies Press, Washington, D.C. 8. “FDA Approves Pyridostigmine as Pretreatment for Nerve Gas:” Press Release PO3-08. 2003. Food and Drug Administration. February 5, 2003. www.fda.gov/bbs/topics/NEWS/ 2003/NEW00870.html. 9. DiMasi JA et al., The price of innovation: new estimates of drug development costs, J Health Econ 22(2):51-185, 2003. 10. IMS Intelligence, Applied, “IMS Global Insights-Lipitor Leads the Way in 2003.” www.imshealth.com/web/con­ tent/0,3148,64576068_63872702_70260998_7 0960214,00.html (July 4, 2006). 11. Commercial Perspectives: Vaccines. Summarized at www.piribo.com/publica­ tions/prescription_drugs/DAT059.html (July 5, 2006). 12. HHS Implementation of Project BioShield. The Subcommittee on Health, Committee on Energy and Commerce, 109th Congress. Testimony of Alex M. Azar, II, Deputy Secretary, Department of Health and Human Services (April 5, 2006), from www.hhs.gov/asl/testify/t060406.html. 13. Pandemic All-Hazards Preparedness Act, December 19, 2006, S.3678.

30 THE JORDAN REPORT 2007 Figure 1 Medical Countermeasures Pipeline

Academia

Pathogen Vaccines Basic Biology Target Preclinical Clinical Therapies Research Identification Development Evaluation Host Diagnostics Response

Industry

NIH “Push” Procurement $5.2 billion (FY02-05) Research + Development Resources HHS “Pull” PROJECT BIOSHIELD $5.6 billion (FY04-13)

Delivery of MCMs* to **Medical Countermeasures the SNS** **Strategic National Stockpile

Figure 2 Project BioShield Acquisition Process

Interagency Approval of the Requirement and Acquisition by WMD MCM Subcommittee Findings by Secretaries of DHS and HHS* � Determination of material threat � Determination that countermeasures are necessary to protect public health � Determination that acquisition of the countermeasure with the Special Reserve Fund (SRF) is appropriate —Numbers of doses required —Production & delivery is feasible within 8 years — Evaluation of commercial market � Joint recommendation that the SRF be made available for the procurement Approval by the President* (Delegated to OMB) HHS Executes Acquisition Program

*Statutory requirements as defined in the Project BioShield Act of 2004 (P.L. 108-276)

PROJECT BIOSHIELD 31 32 THE JORDAN REPORT 2007 Table 1: Summary of Project BioShield Acquisition Programs, 2004-2007

Medical Countermeasure Quantity Funds Obligated/Status of Contract

Anthrax Recombinant Protective Antigen 75 million doses Contract awarded by HHS November (rPA) anthrax vaccine 2004 to VaxGen, Inc. Terminated December 2006: $1.7M.

Anthrax Vaccine Adsorbed (AVA) 5 million doses Contract awarded May 2005 to BioPort Corp.: $122.7M.

Delivery to the Strategic National Stockpile (SNS) was completed in February 2006.

Option for an additional 5 million Contract options exercised in May doses 2006 for an additional 5 million doses: $120M.

Anthrax therapeutics 30,000 treatment courses Two base contracts (non-BioShield) awarded September 2005 for product testing to Human Genome Science ($1.8M) and Cangene Corp. ($0.4M). Monoclonal Antibody to Protective Antigen

Contract options exercised in June 2006 under the Human Genome Sciences contract for 20,000 treatment courses of ABthrax: $165.2M. Human Anthrax Immune Polyclonal Immune Globulin Contract option exercised in July 2006 under the Cangene contract for an additional 10,000 treatment courses of Human Anthrax Immune Globulin: $143.8M.

PROJECT BIOSHIELD 33 Medical Countermeasure Quantity Funds Obligated/Status of Contract

Botulism Botulinum antitoxin 200,000 doses In FY04 prior to enactment of the Project BioShield Act of 2004, $50M was obligated for support of the botulinum antitoxin program. These funds were used to process existing equine plasma collected by the Department of Defense and to establish the equine plasma program needed to provide new plasma for processing into antitoxin.

Contract awarded June 2006 to Cangene Corporation for 200,000 doses of Heptavalent Botulism Antitoxin: $362.6M.

Smallpox Modified Vaccinia Ankara (MVA) 10 million—20 million doses RFP posted August 2005; Proposals received October 2005; Amendment to the RFP released July 2006; Contract award(s) anticipated in May 2007.

Radiological/Nuclear Pediatric (Liquid) Potassium Iodide 1.7 million one-ounce bottles Contract awarded March 2005 to Fleming Pharmaceuticals for 1.7 million bottles: $5.7M.

Additional 3.1 million bottles Delivery to the SNS was completed in September 2005. Contract options exercised in February and May 2006, including an additional 3.1 million bottles: $11.8M.

Total obligation: $17.5M. Delivery to the SNS started in May 2006.

Medical countermeasures to treat/ Up to 100,000 treatment courses RFP closed February 2006. RFP mitigate neutropenia associated with terminated March 2007 and will Acute Radiation Syndrome (ARS) be reissued.

34 THE JORDAN REPORT 2007 Medical Countermeasure Quantity Funds Obligated/Status of Contract

Chelating agents Zn- and Ca-DTPA ~475,000 doses Contract awarded February 2006 to Akron Inc. for delivery of 390,000 doses of Ca-DTPA and 60,000 doses of Zn-DTPA: $21.9M. Obligation increased by $32,448 to acquire an additional ~5,000 doses of Ca-DTPA and ~19,000 doses of Zn-DTPA (manufacturer overage).

Delivery of 395,370 doses Ca-DTPA and 79,369 doses Zn-DTPA to the SNS completed in April 2006.

PROJECT BIOSHIELD 35 Noreen Hynes, M.D., M.P.H. Dr. Hynes served as the Deputy Assistant Secretary for Public Health Emergency Medical Countermeasures, Office of Public Health Emergency Preparedness, Office of the Secretary of Health and Human Services. She has held various positions in government and academia. During her 30 years of government service, Dr. Hynes has focused on research, medical, regulatory and public health aspects of infectious diseases, especially potentially vaccine- preventable diseases including dengue, simian immunodeficiency virus, sexu­ ally transmitted diseases, anthrax, and other biological threat agents. Following the terrorist attacks of 2001, she served as senior advisor for medicine and pub­ lic health in the Office of the Vice President of the United States and played a role in the development of Project BioShield.

36 THE JORDAN REPORT 2007 Using Genomics to Identify Novel Vaccine Candidates Against Pathogens

Hervé Tettelin, Ph.D., Rino Rappuoli, tests against the pathogen itself as a final are likely to be exposed at the surface of Ph.D., and Claire M. Fraser-Liggett, Ph.D. step prior to clinical trials. the bacteria. Surface-exposed proteins The reverse vaccinology approach are predicted based on the combination Introduction was pioneered in 2000 using the genome of several pieces of evidence including he Genomes Online Database sequence of serogroup B Neisseria proteins known to carry out functions at (www.genomesonline.org) lists meningitidis [1, 2]. N. meningitidis is a the surface of the cell, exclusion of proteins T more than 2,000 genome Gram-negative bacterium that causes known to be cytoplasmic, and exclusion sequencing projects, including more life-threatening invasive infections, of proteins likely to be embedded in the than 1,000 bacterial projects that are meningitis and septicemia, especially in cell’s membrane and inaccessible to anti­ either completed or ongoing. The vast young infants. While vaccines were avail­ bodies. Additional evidence contributing majority are accessible to the public. able against four of the five pathogenic to predictions is based on amino acid This wealth of genome sequence infor­ serogroups of N. meningitidis, none existed motifs characteristic of targeting to the mation enables a sizeable repertoire of against serogroup B. The serogroup B membrane (signal peptides), anchoring large-scale analyses geared at under­ capsular polysaccharide is a polysialic in the lipid bilayer (lipoproteins), standing the biology, phylogeny, and acid that could not be used for vaccine anchoring in the outer membrane of genetic diversity of organisms of interest. development because its structure is Gram-negative bacteria or the cell wall of In the case of pathogens, critical insights identical to carbohydrates widely dis­ Gram-positive bacteria (like streptococci), into their potential to interact with their tributed on human glycoproteins such as and interacting with host proteins or host and cause disease can be gleaned N-CAM. In addition, candidate proteins structures (e.g., integrin binding domain) from comparative and functional identified through classical approaches [4]. This analysis typically identifies genomics approaches. In particular, consistently provided high levels of pro­ several hundreds of predicted surface- genomics can be used extensively to tection against their homologous strain exposed proteins. In the case of N. accelerate the development of vaccines but failed to confer general protection meningitidis serogroup B, 570 candidates by enabling the in silico identification of due to their high degree of sequence were identified. promising vaccine candidates prior to variability across isolates. Application of undertaking any experimental step of the reverse vaccinology approach [2] Experimental Characterization of classical vaccine development. identified several highly immunogenic Vaccine Candidates and highly conserved (non-variable) The next step in reverse vaccinology is to Reverse Vaccinology vaccine candidates, and a subset of these experimentally characterize the predicted Reverse vaccinology is an approach that is currently being tested in human clinical candidates. The potential surface proteins reverses the steps of classical vaccine trials [3]. are expressed in Escherichia coli and the candidate discovery and alleviates the purified recombinant proteins are used need to grow the causative organism. In Silico Vaccine Candidate Prediction for immunization of mice. Antisera A gene list derived from the complete For many bacterial pathogens, human raised against the injected proteins are genome sequence of a pathogen of immunity is mediated by raising antibodies recovered and assayed for specificity by interest is used to predict gene products against epitopes accessible at the surface Western Blot. Accessibility of the candi­ (proteins) that are likely to be accessible of the pathogen. In silico analysis, which date proteins on the surface of pathogen to host antibodies. The potential candi­ uses computer-based modeling in con­ is also tested by flow cytometry or dates are then expressed and character­ junction with bioinformatics, enables immunoprecipitation using the antisera. ized experimentally, including serological systematic identification of proteins that Finally, the antisera can be combined in

USING GENOMICS TO IDENTIFY VACCINE CANDIDATES 37 vitro with human complement to assay in neonates in the United States and fully assess the expected degree of diver­ bacterial killing (bactericidal activity) Europe [6]. It is also an emerging cause sity among disease-causing strains likely [5] that often correlates with protection of infection in the elderly [7, 8]. The to be encountered in the field, it is in humans. Each experimental step of reverse vaccinology approach was applied preferable to have access to the genome the process reduces the number of poten­ to serotype V strain 2603V/R of S. sequence of multiple strains and perform tial vaccine candidates to a refined set of agalactiae, which is a representative of up-front genome comparisons prior to proteins that satisfies all the criteria and an emerging serotype responsible for undertaking the development of vaccines warrants high probability of success for one-third of clinical isolates in the United based on genome data. the development of a vaccine. It is States [9]. Mining of the 2603V/R genome Unfinished genome sequences (no important to note that candidates are sequence predicted 650 surface-associated gap closure) are of interest because they not required to be directly involved in proteins, 291 of which were successfully are much cheaper to produce than com­ virulence to confer protection when used expressed. Fifty-five proteins were acces­ pleted genomes. Indeed, much of the in a vaccine; indeed, surface exposure sible to antibodies tested against the effort and costs of a genome project are and antigenicity are sufficient. pathogen. A number of strong candidates dedicated to the finishing phase because For N. meningitidis serogroup B, 350 were selected for vaccination in the animal it is time consuming, less amenable to of the 570 candidate surface proteins model. Unfortunately, no candidate or automation, and less predictable. However, were successfully expressed as recombinant combination thereof conferred general it is important to have at least one, but proteins. Of these, 85 were strongly positive protection against a diverse panel of S. preferably several, complete genome in at least one of the experimental tests agalactiae isolates. Microarray-based sequences of the strains of interest in listed above. The seven best candidates comparative genomic hybridizations order to understand the structure of that satisfied all criteria were selected revealed that S. agalactiae is an extremely their chromosomes and identify regions and sequenced across a panel of diverse diverse species [9, 10]. Most of the diversity that are not obtained by shotgun sequenc­ strains of N. meningitidis representing all was restricted to several large genomic ing without targeted gap closure [12]. serotypes and spanning the phylogeny of islands whose presence and absence var­ the species [2]. Five of the seven candidates ied among strains, but several individual The Pan-Genome Concept were completely conserved across the genes also varied. This degree of diversity In order to assess the genetic diversity of entire panel of strains. Thus, for the first indicated that multiple genomes of this the S. agalactiae species, the gene content time in decades of classical vaccinology, species should be used to enable the of eight whole genome sequences (three five extremely strong vaccine candidates identification of broadly protective vaccine finished and five unfinished) was com­ likely to confer general protection against candidates. It was thus decided to generate pared to identify genes shared among all serogroup B strains of N. meningitidis the complete genome sequence of six or some of the isolates studied as well as were identified. These were combined additional strains of S. agalactiae repre­ genes that are specific to individual strains and tested in infant rats challenged senting the major disease-causing [11, 13]. intraperitoneally with lethal doses of N. serotypes of S. agalactiae [11]. The genes shared by all the strains meningitidis. The cocktail, when formu­ constitute the core genome and represent lated with adjuvants suitable for human Bacterial Species Diversity the machinery that enables S. agalactiae use, conferred protection in rats against Comparing Multiple Genome to achieve its basic life cycle and encode 90 percent of a panel of 85 N. meningitidis Sequences from the Same Species its major phenotypic traits. S. agalactiae strains representative of the global popula­ The availability of the complete genome has a core genome made up of 1,806 tion diversity [3]. The cocktail is currently sequence of a single representative strain genes that represent about 85 percent of being tested in human clinical trials [3]. of a pathogen is useful in revealing its any individual genome. This core genome core machinery and comparing it to encodes a wide variety of cellular functions Streptococcus agalactiae or Group B other sequenced species. However, it mostly dedicated to housekeeping. Streptococcus does not provide information about the Analysis of strain-specific genes resulted S. agalactiae is the leading cause of bacte­ diversity encountered across multiple in 13 to 61 genes unique to any individual rial sepsis, pneumonia, and meningitis strains of the species. In order to care­ strain, most of which are clustered in

38 THE JORDAN REPORT 2007 genomic islands, confirming microarray streptococcus) and Staphylococcus aureus. clear leukocytes and rabbit complement, experiments. The flanks of the islands are In contrast, the analysis of 11 Bacillus a strong indicator of a promising vaccine conserved across the genomes, making anthracis genome sequences revealed candidate. Again, the most efficient them potential hot spots for recombina­ that 4 genomes are sufficient to identify killing was achieved with sera from mice tion, possibly with DNA of foreign origin the entire gene repertoire of this species, vaccinated with the four-protein cocktail, acquired through lateral gene transfer. indicating that it has a closed pan-genome. indicating that the protection each anti­ Indeed, many of the islands display an gen confers complements that of the atypical nucleotide composition when Pan-Genome and Reverse Vaccinology other antigens [14]. compared to the rest of their respective Vaccine candidates encoded by the core genomes [11]. The 358 strain-specific genome are more likely than non-core Conclusion genes plus the genes that are present in candidates to be present on all strains Reverse vaccinology alleviates a major some strains but absent in at least one of encountered during infection and there­ problem inherent to classical approaches to them constitute the dispensable genome, fore provide universal protection. This vaccine development that identify only a which includes functions that enable a probably holds true for some pathogenic limited number of highly accessible subset of strains to adapt to specific species. In the case of S. agalactiae, how­ and/or highly expressed antigens. All conditions, colonize particular niches, or ever, no individual core protein or com­ potential antigens are encoded by the resist certain antibiotics. bination thereof provides high levels of pathogen’s genome, and a systematic The combination of the core genome immunity against a panel of S. agalactiae prediction and characterization of all and the dispensable genome constitutes isolates. This could be due to the fact possible candidates results in a large the pan-genome of S. agalactiae. The that these core genes are absent in strains number of antigens available for vaccine pan-genome contains a large number of that have not been sequenced. Another development. The approach has been genes that exceeds that of any given strain factor is that not all potential candidates applied to a growing number of eukary­ and delineates the entire pool of gene are accessible to antibodies in vivo, for otic and prokaryotic species, including functions that are accessible to this species. instance because of the presence of capsu­ the following bacteria: N. meningitidis Analysis of the S. agalactiae pan-genome lar polysaccharides. The best four candi­ [1-3], S. agalactiae [9, 11, 14], S. pneu­ reveals that new genes are added to the dates identified through the screening moniae [15], S. pyogenes [16], pan-genome every time a new genome is process described above include only Porphyromonas gingivalis [17], sequenced. The first genome sequence one protein from the core genome while Chlamydia [18], S. aureus [19], and the provides approximately 2,200 genes, the three other candidates belong to the SARS coronavirus [20, 21]. addition of a second genome provides dispensable genome. Each candidate was While a single genome sequence approximately 100 new genes, a third used individually in protection assays. proved sufficient for the design of a genome brings about 60 new genes, and They conferred 0 to 88 percent protection vaccine against a specific serogroup of so on. Surprisingly, mathematical individually when tested against a panel N. meningitidis, species with an open extrapolation of the observed trend of 6 challenge S. agalactiae strains pan-genome encode too much diversity indicates that every new genome will belonging to the 5 major disease-causing to enable identification of reliable candi­ contribute an average of 33 additional serotypes. The best results in protection dates from a single genome sequence. new genes to the pan-genome no matter were only achieved when the four best The availability of a single genome is how many genomes are sequenced, pos­ candidates were combined together. The further limited by the fact that the first sibly expanding the pan-genome to four-protein cocktail conferred 59 to genome sequence of a given species is infinity [11]. This led to the concept of 100 percent protection against a panel of typically the type of strain that is well an open pan-genome indicating that the 12 S. agalactiae isolates that included the characterized and genetically tractable S. agalactiae species has access to a very major serotypes as well as two strains but often poorly represents the gene large and possibly unlimited number of from the less common serotype VIII repertoire and diversity encountered in genes. Similar results were obtained by (81 percent and 94 percent protection). the wild [22]. Fux et al. further indicate analyzing the available genome sequences Finally, bacterial killing was assayed in that “this limitation might be overcome of Streptococcus pyogenes (Group A vitro in the presence of polymorphonu­ by the summation of individual genomes

USING GENOMICS TO IDENTIFY VACCINE CANDIDATES 39 to produce a species-specific virtual nology with large-scale comparative “supragenome” that corresponds to our genomics provides for a more informed definition of the pan-genome [22]. Shen selection of vaccine candidates and et al. surveyed the supragenome (pan- increases the chances of obtaining a genome) of non-typeable strains of successful vaccine product. These Haemophilus influenzae through low approaches should also be combined pass whole genome sequencing [23]. with functional genomics studies such as They concluded that each strain con­ microarray transcriptional profiling and tained about 10 percent of new genes proteomics to characterize the level, and that the supragenome of H. influen­ localization, and timing of protein expres­ zae is significantly larger than the sion. Indeed, such data allow refining of genome of any individual strain. the candidate selection such that the Most of the recent genome sequenc­ antigens best suited to tackle the pathogen ing efforts were based on the classical and its lifestyle, including its mode of Sanger dideoxy-sequencing or chain interaction with the host, are pursued. termination method, which has been Ultimately, the entire process— greatly automated by the use of capillary whole genome sequencing of multiple sequencing machines. More recently, isolates of a pathogen followed by in silico however, novel sequencing technologies analyses and experimental characterization that allow for higher throughput and of the promising candidates—needs to greater levels of automation have emerged be streamlined and automated in order as viable complements to the Sanger to get to the human clinical trial stage methods [24]. A very promising novel faster and with better candidates. Efforts technology is based on the automation funded by the National Institute of Allergy of the pyrosequencing technique that and Infectious Diseases are currently under was applied to the resequencing of a way to (1) generate the sequence of multi­ number of species, including some ple strains of many important pathogens pathogens with an open pan-genome under the Microbial Sequencing Centers [25]. While this technology is currently (www.niaid.nih.gov/dmid/genomes/mscs), limited by short sequence read length and (2) produce databases and interfaces (100-150 nucleotides) and the inability to enable large-scale genome comparisons to accurately determine the number of and data mining of these pathogen bases in homopolymeric nucleotide genome sequences under the Bioinfor­ tracts (e.g., eight As in a row), it holds matics Resource Centers (www.niaid. great promise for sequencing many nih.gov/dmid/genomes/brc). These additional genomes of species of interest efforts, combined with microarrays, pro­ cheaply and rapidly when a complete teomics, and the exploration of medium reference genome is already available. It to high throughput platforms for the is predicted that within the next few immunological characterization of can­ years this and other new technologies didates such as the VaxDesign system will revolutionize the ability to sequence (www.vaxdesign.com) hold promise to hundreds of genomes of species of inter­ remarkably accelerate vaccine develop­ est and provide the amount of data that ment in the very near future. will enable proper determination of any species’ pan-genome. The combination of reverse vacci­

40 THE JORDAN REPORT 2007 References 16. McMillan DJ et al., Identification and assess­ 1. Tettelin H et al., Complete genome sequence ment of new vaccine candidates for group A of Neisseria meningitidis serogroup B strain streptococcal infections, Vaccine 2004;22(21­ MC58, Science 2000;287(5459):1809-1815. 22):2783-2790. 2. Pizza M et al., Identification of vaccine candi­ 17. Ross BC et al., Characterization of two outer dates against serogroup B meningococcus by membrane protein antigens of Porphyromonas whole-genome sequencing, Science 2000; gingivalis that are protective in a murine 287(5459):1816-1820. lesion model, Oral Microbiol Immunol 3. Giuliani MM et al., A universal vaccine for 2004;19(1):6-15. serogroup B meningococcus, Proc Natl Acad 18. Grandi G, Rational antibacterial vaccine Sci USA 2006;103(29):10834-10839. design through genomic technologies, Int J 4. Telford JL et al., Vaccines against pathogenic Parasitol 2003;33(5-6):615-620. streptococci, in Genomics, Proteomics and 19. Etz H et al., Identification of in vivo expressed Vaccines, G. Grandi, Editor. 2004, John Wiley vaccine candidate antigens from and Sons Ltd: London, United Kingdom:205­ Staphylococcus aureus, Proc Natl Acad Sci USA, 222. 2002;99(10):6573-6578. 5. Goldschneider I et al., Human immunity to 20. Bukreyev A et al., Mucosal immunisation of the meningococcus. I. The role of humoral African green monkeys (Cercopithecus antibodies, J Exp Med 1969;129(6):1307-1326. aethiops) with an attenuated parainfluenza 6. Schuchat A and Wenger JD, Epidemiology of virus expressing the SARS coronavirus spike group B streptococcal disease. Risk factors, protein for the prevention of SARS, Lancet prevention strategies, and vaccine develop­ 2004; 363(9427):2122-2127. ment, Epidemiol Rev 1994;16(2) 374-402. 21. Yang ZY et al., A DNA vaccine induces SARS 7. Harrison LH et al., Serotype distribution of coronavirus neutralization and protective invasive group B streptococcal isolates in immunity in mice, Nature 2004;428(6982): Maryland: implications for vaccine formula­ 561-564. tion. Maryland Emerging Infections Program, 22. Fux CA et al., Can laboratory reference strains J Infect Dis 1998;177(4): 998-1002. mirror “real-world” pathogenesis? Trends 8. Tyrrell GJ et al., Invasive disease due to group Microbiol 2005;13(2):58-63. B streptococcal infection in adults: results 23. Shen K et al., Identification, distribution, and from a Canadian, population-based, active expression of novel genes in 10 clinical isolates laboratory surveillance study-1996. Sentinel of nontypeable Haemophilus influenzae, Infect Health Unit Surveillance System Site Immun 2005; 73(6):3479-3491. Coordinators, J Infect Dis 2000;182(1):168­ 24. Tettelin H and Feldblyum TV, Genome 173. sequencing and analysis, in Genomics, 9. Tettelin H et al., Complete genome sequence Proteomics and Vaccines, G. Grandi, Editor. and comparative genomic analysis of an 2004, John Wiley and Sons Ltd: London, emerging human pathogen, serotype V United Kingdom:45-73. Streptococcus agalactiae, Proc Natl Acad Sci 25. Margulies M et al., Genome sequencing in USA 2002;99(19):12391-12396. microfabricated high-density picolitre reac­ 10. Brochet M et al., Genomic diversity and evo­ tors, Nature 2005;437(7057):376-380. lution within the species Streptococcus agalac­ tiae, Microbes Infect 2006;8(5):1227-1243. 11. Tettelin H et al., Genome analysis of multiple pathogenic isolates of Streptococcus agalac­ tiae: Implications for the microbial pan- genome, Proc Natl Acad Sci USA 2005;102:13950-13955. 12. Fraser CM et al., The value of complete microbial genome sequencing (you get what you pay for), J Bacteriol, 2002;184(23):6403­ 6405. 13. Medini D et al., The microbial pan-genome, Curr Opin Genet Dev 2005;15(6):589-594. 14. Maione D et al., Identification of a universal Group B streptococcus vaccine by multiple genome screen, Science 2005;309(5731):148­ 150. 15. Wizemann TM et al., Use of a whole genome approach to identify vaccine molecules afford­ ing protection against Streptococcus pneumo­ niae infection, Infect Immun 2001;69(3): 1593-1598.

USING GENOMICS TO IDENTIFY VACCINE CANDIDATES 41 Hervé Rino Claire M. Tettelin, Rappuoli, Fraser-Liggett, Ph.D. Ph.D. Ph.D. Dr. Tettelin is Dr. Rappuoli is Dr. Fraser-Liggett Associate Investi­ the Global Head currently heads gator in the for Vaccine the University of Department of Research at Maryland School Microbial Novartis Vaccines of Medicine’s Genomics at The and Diagnostics. Institute of Institute for Genomic Research. His gen­ His education includes a Ph.D. in biologi­ Genome Sciences. She previously served eral interests are using genomics, com­ cal sciences from the University of Siena, as President, Director, and co-founder of parative genomics, and functional and training at Rockefeller University and The Institute for Genomic Research genomics to understand bacterial diversity Harvard Medical School. (TIGR). Starting with her work in 1995 on and virulence, study host-pathogen inter­ The main theme of Dr. Rappuoli’s the first bacterial genome to be sequenced, actions, and identify vaccine candidates research has been bacterial pathogenesis. Dr. Fraser-Liggett has been an international and drug targets to cure disease. Understanding the molecular mechanisms leader in the field of microbial genomics During his Ph.D. thesis, Dr. Tettelin by which pathogens cause disease was and forensics. She has served on several coordinated the work of 25 laboratories used as a means for the rational design National Research Council committees on for sequencing yeast chromosome VII. of innovative tools to prevent infection. applying genomics to medicine, agricul­ Upon joining TIGR, he was the primary Research activities have included the ture, and biodefense and was appointed person responsible for the bioinformatic pathogens Corynebacterium diphtheriae, in 2005 to the National Science Advisory analysis of chromosome 2 of the human Bordetella pertussis, enteropathogenic Board for Biosecurity, a high-level board malarial parasite P. falciparum. Since Escherichia coli, Vibrio cholerae, Heli­ that promotes biosecurity in life science then, Dr. Tettelin has led several published cobacter pylori, and meningococcus. research. She has served on review commit­ whole genome projects on human He is the co-founder of the field of tees of the National Science Foundation, pathogens including N. meningitidis, S. cellular microbiology, a discipline that Department of Energy, and the NIH. She pneumoniae, multiple strains of S. agalac­ has merged cell biology and microbiology. has published more than 220 articles in tiae, E. chaffeensis, A. phagocytophilum, He is a member of the U.S. National scientific journals, has edited three and N. sennetsu. Dr. Tettelin is also the Academy of Sciences and of the European books, and serves on the editorial boards principal investigator for microarray­ Molecular Biology Organization. In 2005, of five scientific journals. based functional genomics projects on he was awarded the Gold Medal by the Dr. Fraser-Liggett’s academic and these and other pathogens, conducting President of the Italian Republic for his professional honors have included the studies both at the DNA level (compara­ contributions to public health care. 2005 Promega Bio-technology Research tive genome hybridizations), and the RNA Dr. Rappuoli has developed the first Award from the American Society of level (transcriptional profiling). recombinant bacterial vaccine (against Microbiology, the 2005 Charles Thom Dr. Tettelin is the author of more pertussis) and a conjugate vaccine Award from the Society for Industrial than 50 papers in the field of genomics. against meningococcus C. Both products Microbiology, the 2002 E. O. Lawrence His most prominent scientific contribu­ have been approved for human use. Award from the Department of Energy, tions relate to pioneering work on the Currently, he is involved in the develop­ election as a Fellow in the American reverse vaccinology approach, in collab­ ment of a vaccine against group B Academy of Microbiology and AAAS, oration with Novartis Vaccines and meningococcus using reverse vaccinology and recognition as one of Maryland’s Top Diagnostics (formerly Chiron Vaccines). (described in this article), the development 100 Women. She holds professorships in This work resulted in new vaccines cur­ of influenza vaccines produced in cell Microbiology and Tropical Medicine as rently being tested in clinical trials and also culture, and the development of vaccines well as in Pharmacology at The George led to the new concept of the bacterial pan- against avian influenza. Washington University School of Medicine. genome (both described in this article).

42 THE JORDAN REPORT 2007 Adolescent Immunizations Will the Shots Hit Their Targets?

Amy B. Middleman, M.D., M.P.H., horizon for adolescents have focused a the past 10 years, such as hepatitis B and M.S.Ed. spotlight on this age group’s likelihood varicella. Although the data include of achieving high vaccination completion shots that are completed per parent New Immunizations for rates. The question is: Will these new shots recall and not necessarily confirmed by Adolescents hit their marks? What are the factors provider record, the National Health dolescent immunizations are influencing the likelihood of adolescent Interview Survey, the Centers for currently being recommended at immunization, and what are some pos­ Disease Control and Prevention (CDC), A a rapid pace. Prior to May 2005, sible strategies to address these factors? and the National Center for Health the only routine adolescent vaccination Statistics (NCHS) indicate that rates of recommendation was for the tetanus/ Adolescent Immunization Rates immunization for hepatitis B and varicella diphtheria booster (Td). Hepatitis B When tracking adolescent vaccination vaccines remain significantly higher vaccination has been recommended completion rates for vaccines such as among younger children age 19 to 35 universally as a catch-up for all adolescents hepatitis B, which has been recommended months than for adolescents [5]. For some who have not previously received the universally for neonates since the early experts, these data indicate that adolescents vaccine, and adolescents who have not 1990s as well as for catch-up among are “traditionally” non-compliant with yet received the varicella vaccine or adolescents, it is clear that vaccination vaccination regimens, and that the only second measles, mumps, rubella (MMR) rates of adolescents have risen steeply in way to achieve successful immunization vaccine should also receive these vaccina­ recent years. National data from commer­ rates is to immunize when children tions as soon as possible. Other vaccines, cial health maintenance organizations are young. including the hepatitis A vaccine, pneumo­ indicate that in 2004, for example, 67 coccal vaccine, and the influenza vaccine, percent of adolescents had received three The Provider and Patient have been recommended for adolescents doses of hepatitis B vaccine by the age of Factors Affecting Adolescent in certain high-risk groups. In May 2005, 13 years, compared to 18 percent in 1997 Immunization the Advisory Committee on Immunization [3, 4]. Interpreting these data is difficult There are some challenges inherent in Practices (ACIP) recommended routine as the data sets do not reveal the year in reaching adolescents, and multiple factors vaccination of adolescents with conjugate which the shots were given. Thus, one contribute to the difficulty in immunizing meningococcal vaccine (MCV4). The can not discern if rates are going up the adolescent age group. Some of them vaccination was recommended for the among adolescents due to more shots are provider/systems-based factors and 11- to 12-year age group with catch-up being given to adolescents themselves, some are patient/parent-based factors; recommended for those approximately due to the aging of immunized infants however, interestingly, these two factions 15 years of age and those entering college who are now adolescents and are up to have many concerns in common (see eand exp cting to live in dormitories [1]. date from childhood immunization, or Figure 1). The oft-cited barriers for In June 2006, the ACIP also recommended some combination of these two possibil­ providers include not seeing enough that the human papillomavirus (HPV) ities. Unfortunately, although the rates adolescents, lack of time during the visit, vaccine be administered routinely to are rising, they are still below the reimbursement concerns, difficulty females age 11 to 12 years, with catch-up Healthy People 2010 goal of 90 percent accessing and verifying past immuniza­ among females age 13 to 26 years (9- to coverage among adolescents 13 to 15 tions, and lack of confidence/self-efficacy 10-year-olds may also be immunized if years of age for all universally recom­ in addressing adolescent issues—especially edesir d) [2]. These new vaccine recom­ mended vaccinations, especially for those related to reproductive health. mendations and new vaccines on the those vaccinations recommended within Patient/parent issues include lack of

ADOLESCENT IMMUNIZATIONS 43 knowledge regarding vaccine-preventable and patient behavior [6, 11]. With the important determinant of parent and diseases and the associated vaccines, lack advent of the Vaccines for Children adolescent acceptability [22]. Data also of time, reimbursement concerns, trans­ Program (VFC) in 1994 as well as state support the role of education in deter­ portation issues, and lack of self-efficacy children’s health insurance programs, mining parental support of vaccination in getting to provider visits. All of these public funding has increased to provide [19]; parents who received education factors potentially influence each other vaccinations to children from birth to regarding HPV were more likely to indi­ to determine the likelihood of adolescent the nineteenth birthday for those who cate acceptance of vaccination than those immunization. are eligible. Improved funding, which is not receiving an educational intervention. a response to Healthy People 2000 goals Providers also indicate support for vac­ Are Providers Seeing Adolescents? requiring increased immunization rates cination in general; a national survey of Although the impression is that providers among children, has had a significant U.S. physicians in 1997 revealed that are not seeing adolescents, the data indi­ impact on immunization completion even then, 82 percent recommended cate otherwise. In fact, although data rates. In 2004, for example, VFC purchased hepatitis B vaccination for all eligible from the Health Plan Employer Data an estimated 40 percent of all of the adolescents, and 84 percent preferred and Information Set indicate that only doses of childhood vaccines distributed that immunizations be administered at 34 percent of adolescents access annual in the United States [12]. Many insurance their own practices [23]. However, it may preventive visits within the health plan companies follow VFC resolutions to be an overstatement to assert that the population [6], 2003 data from NCHS determine coverage for specific vaccines. key factor in immunization is a parent’s indicate that 86 percent of children 6 to Funding for vaccination of young adults or patient’s complete understanding of 17 years of age and 76 percent of adoles­ over the age of 19 years is more complex; the disease and the vaccine being con­ cents and young adults age 18 to 24 years there are some funding streams that can sidered. Anecdotally, most parents (and reported at least one visit to a doctor’s be utilized, including federal dollars via some providers) are not aware of the office or emergency department or a Vaccination Assistance Act, Section 317 specifics of diphtheria and yet immu­ home visit within the past 12 months funds. Overall, improved reimbursement nization rates against this disease remain [7]. Studies support that the majority for vaccinations, especially for children high. There are clearly other factors (88 to 92 percent) of adolescents have an and adolescents, has impacted immuniza­ influencing immunization. The general identified source of primary care [8, 9]. tion rates. Financial policy discussions recognition and parental and provider Data indicate that it is more likely that a are ongoing [13, 14], and, with increasing expectation of compliance with established younger adolescent will present for pre­ numbers of vaccinations available, con­ immunization visits during the adolescent ventive care; in addition, research supports tinued change in policy is required to years is a critical component to vaccination that physicians are more likely to screen improve immunization rates for all. compliance. for and provide vaccination to younger adolescents [10]. Although parents and Parent/Patient/Provider Education How to Address These Factors patients cite time and transportation as There is a significant body of literature The Society for Adolescent Medicine barriers to immunization, adolescents emphasizing positive adolescent and (SAM) has developed position state­ are accessing the health system at a rate parent perceptions regarding the use of ments to address many of the barriers to that could be exploited for increased adolescent immunizations, including successful immunization of adolescents immunization compliance. The oppor­ those pertaining to reproductive health [24]. They include tunity is there to capitalize on these visits [15-20]. In a concrete sense, parents are (1) The use of all ACIP-recommended and encourage patients and providers clearly important for transportation, vaccines and vaccination schedules alike to avoid missed opportunities for insurance coverage, and authorization in the adolescent age group, without vaccination. for vaccination, but studies also indicate prejudice against the type of infection that parental influence regarding vacci­ or mode of transmission targeted by Reimbursement nation is an important factor affecting the vaccine. Reimbursement for immunization is an adolescents’ vaccination decisions (2) The development of three distinct important concern affecting provider [21,22]. Provider acceptability is an adolescent immunization visits/plat-

44 THE JORDAN REPORT 2007 forms for adolescents (11- to 12­ tion of health care providers, parents, and the potential use of alternative year visit, 14- to 15-year visit, and and teens regarding the health pro­ immunization sites to augment the 17- to 18-year visit) to integrate and motion benefits of immunization options for immunizations and multi- emphasize the role of vaccination in against vaccine-preventable disease. dose series completion for busy families. already recommended comprehensive These positions promote a relatively The issue of reimbursement for vaccina­ health care screening and provision complex assortment of approaches that tions, already discussed above, will also visits. The 11- to 12-year platform is include strategies to improve adolescent require continued advocacy from multi­ the primary immunization platform immunization rates, some of which must ple constituencies (see Figure 2). promulgated by ACIP. SAM endorses be implemented at a public health level emphasizing a 14- to 15-year visit/ and some at a more individual provider/ Public Health Solutions to platform as a time to catch-up on client level. Individualized practice Help “Hit the Targets” missed vaccines or complete multi- strategies that have a history of improving The Need for Established Adolescent dose regimens, and a 17- to 18-year compliance among other target groups, Immunization Platforms visit/platform as an opportunity to such as education, the use of standing Historically, there has been no immu­ update all vaccinations that may orders, the implementation of recall nization platform for adolescents. have been missed or are newly rec­ systems, the simultaneous administration Immunizations have been emphasized ommended while the patient is still of vaccines, and the use of non-compre­ for infants and young children and for covered by third-party payers, hensive visits for vaccinations, will only very good reason: the majority of deaths including the VFC program. be implemented after a priority on ado­ from vaccine-preventable diseases occur (3) The use of standing immunization lescent preventive care in general, and in these age groups. The structure for orders, immunization screening adolescent immunization in particular, effective and efficient immunization of tools, immunization registries, has evolved. Study has revealed that one infants and children has been in place immunization reminder systems of the most important factors in provider for many years. The first “official” (for both provider and patient), and acceptability regarding immunizations is immunization schedule published in recall systems, whenever available, to the recommendation and standard of 1983 by the CDC depicts the immuniza­ increase rates of vaccination among care developed by national standards tion visit structure for infants and children this age group. promulgated by their own professional that had been developing in the United (4) The simultaneous administration of organizations [25]. States since the introduction of the multiple vaccines to increase vacci­ It will most likely be the changes that diphtheria, pertussis, tetanus (DPT) nation rates and utilize/capitalize on occur at a public health level as a result vaccine in the 1940s. The only adolescent currently required and mandated of evidence-based deliberation that will immunization recommendation at that vaccination regimens. stimulate the most significant changes in time was for the Td booster at age 14 to (5) The use of “non-comprehensive” the ultimate vaccination behavior of 16 years. Adolescents’ importance in the visits (e.g., minor illness visits, both providers and patients. The key overall scope of the early immunization camp/sports physicals, pre-college public health constructs that could schedules is perhaps most clearly repre­ visits) and qualified “alternative” potentially change the culture of adoles­ sented by their complete omission from vaccination sites (e.g., pharmacies, cent immunization include: the develop­ the 1994 schedule [26, 41]. Now, as the schools) for adolescents unable to ment of distinct and expected idea of using immunization to protect access comprehensive preventive care. adolescent immunization platforms/ against disease across the life span bur­ SAM urges the alternative vaccination visits; continued mandates requiring geons, the establishment of immunization sites to provide adolescent clients vaccination for school entry (a state- platforms that encompass older children with referral lists of adolescent care level issue at this time); resources and in the adolescent age range and provide providers in their area as well as emphasis placed on the use of immu­ an expectation and standard of care to appropriate adolescent health edu­ nization registries that will prevent over- be followed would address a significant cation materials. and under-immunization of adolescents barrier to adolescent immunization (6) The continued and increased educa­ who often visit multiple sites for care; completion.

ADOLESCENT IMMUNIZATIONS 45 The same parents who brought their immunizations and immunization catch­ for freshmen entering college, vaccine children in for infant and child immu­ up will increase the likelihood of delivery supply requirements to colleges have nizations are, for the most part, the same of other preventive health services. been decreasing as more providers have parents who will bring in their children ACIP has been methodical in its started immunizing in the medical as adolescents. A large part of the current recommendations for adolescents thus home [personal communication, July difficulty in having parents know to far. Most recommendations are geared, 31, 2006]. Change will take time—and bring their children in to the provider when epidemiologically appropriate, to patience—but the long-term effects are for immunizations is the lack of an the 11- to 12-year age group to build a potentially greater than those associated expected and standard immunization or strong platform that will, with continued only with immunizations. preventive visit. Annual preventive health dissemination, become a national standard Platform development for adolescents care visits for adolescents have been for the immunization of adolescents. will be as important for general preven­ recommended by multiple agencies for Data indicate that younger adolescents tive health care of adolescents as it is for many years; the most notable recommen­ have higher rates of accessing preventive infants. The primary sources of morbid­ dations include Guidelines for Adolescent health care than older adolescents [27]. ity and mortality among adolescents as Preventive Services (promulgated by the One of the greatest challenges will be they begin to change and develop physi­ American Medical Association in 1992), remaining patient as time, education, cally, emotionally, and cognitively are Bright Futures (a Maternal Child Health and resources filter through to help hold the result of risk behaviors. With the Bureau product), U.S. Preventive Health the platform together. Vaccine utilization advent of immunizations, the possibility Task Force recommendations, and recom­ data compiled after the initial recom­ exists that adolescents coming in for the mendations by the American Academy of mendation of MCV4 reveal a pattern effective prevention of vaccine-preventable Pediatrics and the American Association of immunization that could have been disease will also be able to receive further of Family Physicians. However, the pre­ predicted given the lack of immunization services that address multiple health ventive strategies implemented during platforms among the adolescent age care concerns that would otherwise have annual visits rarely include the type of group. Physician claims data through been missed. As new recommendations tangible service such as immunization March 2006 revealed a routine immuniza­ are developed for adolescents, the that draws patients in for care. Although tion across all adolescents regardless of importance of developing a similarly most adolescents eventually receive their age, despite the recommendations for strong structure, upon which the pre­ Td booster and compliance rates for this immunization of 11- to 12-year-olds, ventive health care of adolescents can be vaccination are relatively high, this is 15-year-olds, and 18-year-olds entering built, represents an opportunity to affect most likely due to state mandates and college to live in dormitories [28]. These adolescent health on a scale much larger national recommendations that, although data indicate that without standard and than vaccine-preventable disease alone. variable, have been in place for many established visit patterns for adolescents, years. However, there is no consistent recommendations that target distinct, School Mandates national standard that guides the imple­ intermittent age groupings within the Experience with immunizing adolescents mentation of a distinct immunization adolescent years are unlikely to be followed. against hepatitis B has provided data that platform similar to the one that exists Currently, providers cannot be sure make it quite clear that state mandates for infants and young children. One of when they will see adolescents again and significantly affect immunization rates the most significant barriers to effective are understandably anxious to vaccinate among adolescents in the United States. adolescent immunization delivery is while they have the opportunity. There In a recent study of the effect of school the lack of structure provided by well- have been subtle changes noted, however, mandates, adolescents were significantly established immunization platforms as adolescent immunization has more likely to have completed the hepa­ that so efficiently guide the parents of increased over the past several years. In a titis B vaccination series in states with younger children. It is also important to personal communication with sanofi­ mandates (75 percent) versus in states establish further immunization platforms pasteur, it was noted that as providers without mandates (39 percent, p<0.001) within the adolescent age range as sug­ have developed familiarity with the [29]. A study was conducted during the gested by SAM. Multiple encounters for meningococcal vaccine recommendation year before and year after a new state

46 THE JORDAN REPORT 2007 law was passed in California requiring tion of vaccinations (same day, different country, and given the strong possibility that students entering the seventh grade anatomic sites), and by taking advantage that alternative sites will be used for have received three doses of hepatitis B of immunization mandates that are immunization among the adolescent age vaccine and two doses of MMR. The already in place, immunization rates for group as well as adults, federal and state researchers found that vaccination cov­ all vaccines can be increased. In general, support of registries will be a key com­ erage rates were greatly increased among more coordinated state efforts that ponent to the success of immunization seventh graders in the year after the law reflect national policy recommendations programs across the life span. was put into effect (60 percent) than would help increase immunization rates among fifth and sixth graders the year for all children and adolescents. The Use of Alternative Sites before (13 percent), or eighth through Alternative immunization sites have twelfth graders not affected by the legis­ The Use of Registries been used successfully among adults. lation (27 percent) [30]. Although not By 3 years of age, 25 percent of children Pharmacies, in particular, have played an affected by the law, there was an encour­ in the United States receive immuniza­ ever-increasing role in immunizations aging increase in the vaccination coverage tions from more than one provider [14]. since the 1980s when pharmacies hosted achieved among the eighth to twelfth It is also estimated that 27 percent of nurses to administer vaccines [37]. As of grade group, perhaps indicating that the adolescents use multiple sources of care December 2004, 43 states allow pharma­ educational effects of perceived benefit depending upon the health issues for cists to immunize [38]. Recent research from the law affected immunization which they seek guidance [8]. Providers indicates a high level of safety associated rates among other adolescents and their often have incomplete or inaccurate with mass influenza vaccination clinics in parents. The power of mandates may immunization records, leading to over- non-traditional settings [39]. Pharmacies not only be the direct effect of the actual or under-immunization. The National are becoming increasingly popular sites law on coverage rates in the schools, but Vaccine Advisory Committee and the for adult immunization. the message that is tied to the man- National Immunization Program of the Sites other than the medical home date—that immunizations are deemed CDC advocate the use of computerized for adolescent immunization might an important preventive health strategy immunization information systems (IIS) include schools, city clinics, family for everyone. as a solution to these problems. These planning clinics, gynecology offices, As of July 2006, according to the systems have been shown to increase emergency departments, and pharmacies. Immunization Action Coalition Web site, documented up-to-date rates and pro­ There is evidence that adolescents seek only 14 of the 50 states plus the District vide insights into patterns of immuniza­ care at these sites: in 1994, 14.8 million of Columbia do not have a middle school tion delivery [34]. IIS can consolidate adolescent health visits were to emergency mandate for hepatitis B vaccine [31]. fragmented records, provide immuniza­ departments, 7.3 million were to outpa­ Tetanus, diphtheria, and pertussis booster tion needs assessments for each patient, tient departments, and 5.2 million mandates change relatively frequently, keep track of patients needing recom­ female visits were to family planning but states clearly differ in their mandates mended or catch-up vaccination, pro­ clinics [40]. Approximately 4 percent of and the ages at which they require vide automated reminder, assist in the teens and 11 percent of impoverished immunization, specifically the booster management of vaccine supply, and gen­ adolescents use community clinics for dose for adolescents. There are still many erate vaccination records for parents, routine health care [41]. School clinics states that do not have mandates for the schools, and others [35, 36]. Data as of have already been enlisted in several booster dose of Td or Tetanus, Diphtheria, 2004 indicate that 48 percent of U.S. immunization programs with great success Pertussis vaccine (Tdap) [32, 33]. children are involved in an IIS, and 76 [42-47], and city clinics are already often Despite the success of school mandates percent of public and 39 percent of pri­ used as immunization sites for adolescents. in increasing adolescent immunization vate providers participate, an increase With the advent of the HPV vaccine, it rates, it is unlikely that all adolescent over 2003 numbers [1]. Given the frag­ is expected that gynecology offices will vaccinations will be mandated by each mented health utilization patterns in this also become more involved in the state. By educating providers on the country as insurance plans change and administration of at least some vaccines. importance of simultaneous administra­ people change jobs and move around the An important issue that will need to

ADOLESCENT IMMUNIZATIONS 47 be addressed, especially with the use of consent may vary based on whether the Summary alternative sites for adolescent immuniza­ vaccine addresses reproductive health In general, the individual adolescent is tion, is that of “consent” for adolescent diseases for which adolescents have the not keen on receiving shots. Adolescents vaccinations. The CDC notes in its General ability to consent for confidential care. and young adults report fear of pain and Recommendations on Immunization The details of consent for immuniza­ needles [52, 53]. Until some of the new, that, “the National Childhood Vaccine tions targeting adolescents, especially at less painful immunization delivery systems Injury Act of 1986 (42 U.S.C. § 300aa-26) alternative sites, will be an interesting are marketed, however, adolescents need requires that all health care providers in challenge for public health officials in to access vaccinations in their current the United States who administer any each state. form to be protected against vaccine- vaccine covered by the act must provide The primary morbidity and mortality preventable disease. The public health a copy of the relevant, current edition of among adolescents, however, is not due focus to this point has understandably the vaccine information materials that to vaccine-preventable disease, but, been on immunizing infants and have been produced by CDC before rather, to preventable behaviors [51]. younger children. With the advent of administering each dose of the vaccine. Primary care providers are an important newer vaccines targeting the adolescent The vaccine information material must component in the care of adolescents; age group, the opportunity exists to be provided to the parent or legal repre­ the advent of new vaccine recommenda­ greatly affect adolescent health in general sentative of any child or to any adult to tions could serve as an important impetus in this country. Vaccination is an effective whom the physician or other health care pushing adolescents to receive other preventive measure; the tangible delivery provider intends to administer the vaccine. needed preventive health services. If of such a service will also function as an The Act does not require that a signature alternative sites of immunization are important “carrot” to draw adolescents be obtained, but documentation of made readily available, adolescents may in to providers to receive other critical consent is recommended or required by bypass this opportunity to receive compre­ preventive health care. The key to the certain state or local authorities [48].” It hensive preventive care and opt for the successful implementation of adolescent will be important for states to develop quicker use of an alternative immuniza­ immunization will be patience; each factor and support consent procedures that do tion site. This creates an obvious tension associated with increasing the likelihood not hinder the immunization of adoles­ between the opportunity to provide of adolescent immunization has many cents yet also allow for parents to be effective immunizations to as many complexities associated with it. The involved with the decision to immunize adolescents as possible and the desire to strong structure of infant and childhood when appropriate. Studies have shown deliver more comprehensive preventive immunization was not built particularly that school-based immunization initiatives health care to adolescents. Other potential expeditiously and required significant have experienced parental consent for issues with alternative immunization time and resources. The same will be immunization as the single most difficult sites include poor follow-up and lack of true for an adolescent immunization barrier to immunizing students [49, 50]. access to IIS. However, alternative sites structure. The long-term advantages to In a hepatitis B school-based immuniza­ for immunization seem like a practical building the structure will be multifold: tion initiative in Texas, the state required option for those without a medical home, disease prevention among adolescents, parental consent for each of the three or those who have already received other increased comprehensive care applying doses of vaccine, representing a significant preventive care services and only require to other important health issues, and the barrier to the efficient delivery of the a vaccination to complete a series or establishment of immunization patterns full vaccination series [49]. However, quickly comply with school mandates. that, if successful, could help set the this vigilance is often needed when Studies are being initiated to investigate stage for the public to view immunizations immunizations are administered in the feasibility and acceptability of the use as a lifelong preventive strategy that schools, in particular. Each school district of alternative immunization sites for requires maintenance through adulthood. has the ability to determine what will adolescents among providers and patients. The goal is to have those shots hit their occur within its schools. Each state The results are awaited with interest. targets, and the targets will benefit in determines the level of consent required many ways for a long time to come. for vaccines, and the conditions of this

48 THE JORDAN REPORT 2007 Figure 1: Patient and Provider Factors Associated With the Likelihood of Adolescent Immunization

Education/ Self-Efficacy Knowledge

PATIENT PROVIDER

Insurance/ Time Reimbursement

Patient Likelihood Provider Likelihood to Access to Administer Immunization Immunization

Adolescent Immunization

ADOLESCENT IMMUNIZATIONS 49 Figure 2: Constituencies and Issues Related to Vaccine Reimbursement

PUBLIC POLICY

PROVIDERS NATIONAL STATE Education about provision of Use of recall systems preventive care for adolescents Development Mandates for School Entry of Standard Use of Education about Immunization standing orders immunizations Platforms by ACIP, Professional Use of registries Development of Organizations vaccination “quick visits” State Review of Use of if other services “Consent” Procedures screening tools Bull’s-eye! are not needed Reimbursement/Funding Shots in Adolescent Arms Attend vaccination Education about (currently VFC, 317) “quick visits” if need for preventive other preventive care of adolescents Reimbursement/ services not Funding required Enrollment in (currently SCHIP) Education about immunization registries immunizations Use of alternative site if no Funding and medical home or if need to Support for Registries complete a series of vaccinations Funding and Support PATIENTS for Registries

State Legislation Insurance Reform Allowing Immunization at Alternative Sites

50 THE JORDAN REPORT 2007 References 19. Davis K et al., Human papillomavirus vaccine Delivery of New Vaccines for Adolescents, 1. Bilukha O and Rosenstein N, Prevention and acceptability among parents of 10- to 15-year­ National Stakeholders Meeting, Washington, control of meningococcal disease recommen­ old adolescents, J Lower Genital Tract Dis D.C., June 2-3, 2005. dations of the Advisory Committee on 2004;8:188-194. 39. D’Heilly S et al., Safety of influenza vaccina­ Immunization Practices (ACIP), MMWR 20. Zimet G et al., Predictors of STI vaccine tions administered in nontraditional settings, Recommendation Report 2005;54:1-21. acceptability among parents and their adoles­ Vaccine 3rd International Conference on 2. http://www.cdc.gov/nip/acip/slides/jun06/hpv-6­ cent children, J Adolesc Health 2005; 37:179­ Vaccines for Enteric Diseases 2006;24:4024­ markowitz.pdf accessed July 31, 2006. 186. 4027. 3. http://www.opic.state.tx.us/docs/369_guide­ 21. Rosenthal S et al., Hepatitis B vaccine accept­ 40. Ziv A et al., Utilization of physician offices by tohmoquality2005.pdf accessed July 27, 2006. ance among adolescents and their parents, J adolescents in the United States, Pediatr Ann 4. http://www.ncqa.org/sohc2003/adolescent_ Adolesc Health 1995;17:248-254. 1999;104:35-42. immunization_status.htm accessed July 27, 22. Rosenthal S, Protecting their adolescents from 41. Hedberg VA et al., The role of community 2006. harm: parental views on STI vaccination, J health centers in providing preventive care to 5. http://www.healthypeople.gov/document/ Adolesc Health 2005;37:177-178. adolescents, Arch Pediatr Adolesc Med HTML/Volume1/14Immunization accessed 23. Shaffer S, The coming of age of adolescent 1996;150:603-608. July 31, 2006. immunization, Pediatr Ann 2001;30:342-345. 42. Centers for Disease Control and Prevention, 6. McInerny T et al., Physician reimbursement 24. Middleman A et al., Adolescent immuniza­ Hepatitis B vaccination of adolescents- levels and adherence to American Academy of tions: A position paper of the Society for California, Louisiana, and Oregon, 1992-1994, Pediatrics Well-Visit and Immunization Rec­ Adolescent Medicine, J Adolesc Health MMWR Weekly 1994:43:605-624. ommendations, Pediatrics 2005;115:833-838. 2006;38:321-327. 43. Cassidy W, School-based adolescent hepatitis 7. http://www.cdc.gov/nchs/data/hus/ 25. Raley J et al., , Gynecologists’ attitudes regard­ B immunization programs in the United hus05.pdf accessed July 27, 2006. ing human papillomavirus vaccination: a sur­ States: strategies and successes, Pediatr Infect 8. Klein J et al., Adolescents’ access to care: vey of Fellows of the American College of Dis J 1998;17(7):S43-S46. Teenagers’ self-reported use of services and Obstetricians and Gynecologists, Infect Dis 44. Wilson T, Economic evaluation of a metropol­ perceived access to confidential care, Arch Obstetr Gynecol 2004;12:127-133. itan-wide, school-based Hepatitis B vaccina­ Pediatr Adolesc Med 1998;152:676-682. 26. http://www.cdc.gov/nip/publications/ tion program, Public Health Nurs 9. Klein J et al., Access to medical care for ado­ mmwrpubs.htm#3 accessed July 27, 2006. 2000;17:222-227. lescents: Results from the 1997 27. Rand C et al., Preventive counseling at adoles­ 45. Boyer-Chuanroong L et al., Immunizations Commonwealth Fund Survey of the health of cent ambulatory visits, J Adolesc Health from ground zero: lessons learned in urban adolescent girls, J Adolesc Health 1999;25:120­ 2005;37:87-93. middle schools, J Sch Health 1997;67:269-72. 130. 28. Wallace G, Menactra supply update. Advisory 46. Liu H et al., Hepatitis B catch up project: 10. Oster N et al., Barriers to adolescent immuniza­ Committee for Immunization Practices meet­ Analysis of 1999 data from the Chicago Public tion: A survey of family physicians and pedia­ ing, Atlanta, GA, presented June 30, 2006. Schools, Asian American and Pacific Islander tricians, J Amer Bd Fam Prac 2005;18:13-19. 29. Jacobs RJ and Meyerhoff AS, Effect of middle Journal of Health 2001;9:205-210. 11. Centers for Disease Control and Prevention, school entry requirements on hepatitis B vac­ 47. Middleman AB, Race/ethnicity and gender Vaccine preventable diseases: Improving vacci­ cination coverage, J Adolesc Health disparities in the utilization of a school-based nation coverage in children and adults. A 2004;34:420-423. hepatitis B immunization initiative, J Adolesc report on recommendations from the Task 30. Averhoff F et al., A middle school immuniza­ Health 2004;34:414-419. Force on Community Preventive Services, tion law rapidly and substantially increases 48. Atkinson W et al., General recommendations MMWR 1999;48(RR-8):1-15. immunization coverage among adolescents, on immunization: Recommendations of the 12. www.cdc.gov/programs/immun10.htm/ Amer J Publ Health 2004;94:978-984. Advisory Committee on Immunization accessed August 1, 2006. 31. www.immunize.org/laws/hepb.htm/ accessed Practices (ACIP) and the American Academy 13. Hinman AR, Financing vaccines in the 21st July 31, 2006. of Family Physicians (AAFP), MMWR century: Recommendations from the National 32. http://www.immunizationinfo.org/ accessed Recommendation Report 2002;51:1-36. Vaccine Advisory Committee, Amer J Prevent July 27, 2006. 49. Guajardo A et al., School nurses identify barri­ Med 2005; 29:71-75. 33. http://www.immunize.org/accessed July 27, ers and solutions to implementing a school- 14. Hinman A et al., Financing immunizations in 2006. based hepatitis B immunization program, J the United States, Clin Infect Dis 34. Kempe A et al., The regional immunization Sch Health 2002;72:128-130. 2004;38:1440-1446. registry as a public health tool for improving 50. Deeks S and Johnson I, Vaccine coverage dur­ 15. Hoover D et al., Attitudes of adolescent/young clinical practice and guiding immunization ing a school-based hepatitis B immunization adult women toward human papillomavirus delivery policy, Amer J Publ Health program, Can J Public Health 1998;89:98-101. vaccination and clinical trials, Health Care for 2004;94:967-972. 51. http://www.cdc.gov/nchs/data/nvsr/nvsr Woman International 2000;21:375-391. 35. Yawn B et al., The impact of a simulated 53/nvsr53_17.pdf accessed July 31, 2006. 16. Kahn J et al., Attitudes about human papillo­ immunization registry on perceived childhood 52. Slonim A et al., Adolescents’ knowledge, mavirus vaccine in young women, Int J STD immunization status, Am J Manag Care beliefs, and behaviors regarding hepatitis B: AIDS 2003;14:300-306. 1998;4:185-192. Insights and implications for programs target­ 17. Boehner C et al., Viral sexually transmitted 36. Glazner J et al., Using an immunization reg­ ing vaccine-preventable diseases, J Adolesc disease vaccine acceptability among college istry: effect on practice costs and time, Ambul Health 2005;36:178-186. students, Sexually Transmit Dis 2003;30:774­ Pediatr 2004;4:34-40. 53. Nir Y et al., Fear of injections in young adults: 778. 37. Sokos D, Pharmacists’ role in increasing pneu­ Prevalence and associations, Am J Trop Med 18. Olshen E et al., Parental acceptance of the mococcal and influenza vaccination, Amer J Hyg 2003;68:341-344. human papillomavirus vaccine, J Adolesc Health-System Pharm 2005;62:367-377. Health 2005;37:248-251. 38. Schaffer S et al., How effectively can alterna­ tive health care settings provide vaccines to adolescents? Presented at Strengthening the

ADOLESCENT IMMUNIZATIONS 51 Amy B. ing to adolescent immunizations as one Middleman, of the founding co-directors of the new M.D., Texas Children’s Hospital Vaccine Center. M.P.H., Dr. Middleman graduated from Yale M.S. Ed. University with a B.S. in biology; Dr. Middleman University of Pennsylvania School of joined the fac­ Medicine with an M.D.; University of ulty at the Pennsylvania Graduate School of Baylor College Education with an M.S.Ed.; and the of Medicine in January 1997 and is an Harvard School of Public Health with Associate Professor of Pediatrics in the an M.P.H. Adolescent Medicine and Sports Medicine Section. In 2001, she assumed the role of the Director of the Pediatric Core Clerkship and also serves as the section editor in adolescent medicine for the online textbook UpToDate. She is the medical editor of two new books pub­ lished in June 2006 entitled The Girl’s Guide to Becoming a Teen and The Boy’s Guide to Becoming a Teen. In addition to conducting research regarding immunizations among adoles­ cents for many years, Dr. Middleman has been the Society for Adolescent Medicine (SAM) liaison to the Centers for Disease Control and Prevention’s (CDC) Advisory Committee on Immunization Practices since 2004; a member of the Review Panel for the CDC/Ambulatory Pediatric Association/ SAM Immunization Small Grants Program since 2005; and a member of the Be Wise—Immunize Advisory Panel for the Texas Medical Association since January 2006. She has taught mul­ tiple workshops and given updates at national meetings on immunizations among adolescents. Recently, she was the lead author on a position paper for the Society for Adolescent Medicine entitled “Adolescent immunizations: position paper of the Society for Adolescent Medicine,” which was pub­ lished in the Journal of Adolescent Health, March 2006. She continues to write extensively and conduct research pertain­

52 THE JORDAN REPORT 2007 Phase IIB/Test of Concept Trials for HIV Vaccine Efficacy Evaluation

Susan P. Buchbinder, M.D. pivotal licensure trial. They are not candidate [1]. Both Merck and “underpowered Phase III trials.” Instead, GlaxoSmithKline evaluated HPV vaccine mong the many challenges in Phase IIB/TOC trials are designed to candidates initially with Phase IIB/TOC human immunodeficiency virus address a different set of questions than trials [2, 3] prior to moving to pivotal A (HIV) vaccine development, one would a Phase III trial, and, in doing so, Phase III trials [4, 5]. of the most critical is the lack of clearly help in the design and execution of later Only two efficacy trials of HIV vac­ defined immune correlates of protection Phase III trials. cines have been completed to date and from HIV acquisition or development of neither demonstrated efficacy. One trial disease. Although protection has been Questions Addressed in Phase evaluated the AIDSVAX B/B’ vaccine in demonstrated in animal models of IIB Trials North America for protection against closely related retroviral infection, the Phase III trials are designed to evaluate sexually acquired HIV acquisition; the relevance of these models to human the efficacy of promising products, in other evaluated the AIDSVAX B/E’ vaccine protection is not yet known, and no preparation for licensure. However, in injection drug users. Both vaccines clear immune correlates have been iden­ when considerable uncertainty exists included two recombinant glycoprotein tified in human or animal studies. about the likelihood of success of a par­ (rgp) 120 subunit proteins: AIDSVAX Without a clear bar against which to ticular vaccine product or class of products, B/B’ used the laboratory-adapted isolate compare immune responses from vaccine or when additional information is (MN) with a primary clade B isolate candidates in early clinical trials, it is needed to further define the appropriate (GNE8), while the AIDSVAX B/E’ also difficult to define the appropriate time endpoints, target populations, or included the MN component mixed to move these vaccines into efficacy immune correlates of protection, Phase with a primary clade E isolate (A244). evaluation. Efficacy evaluation is further IIB/TOC trials may provide strategic To demonstrate the public health utility complicated by the lack of clear consen­ advantage as an intermediary step of these vaccines, both were also powered sus on appropriate endpoints for HIV between immunogenicity studies and to definitively identify at least 30 percent vaccine trials. Rather than being able to Phase III pivotal trials. In the case of reduction in HIV infection rates in the rely on classic vaccine trial endpoints HIV vaccines, uncertainty currently vaccine recipients. Neither trial demon­ such as protection from acquisition of exists for all four questions: (1) likelihood strated any overall efficacy despite infection or development of clinical dis­ of success; (2) appropriate trial end­ achieving the anticipated humoral ease, HIV vaccine trials may only be able points; (3) appropriate populations; and immune response to vaccine [6-9]. The to measure protection against surrogate (4) immune correlates of protection. combined trials enrolled nearly 8,000 measures of clinical progression, such as volunteers, lasted five years, and are HIV viral load, or time to initiation of Likelihood of Success estimated to have cost $130 million. antiretroviral therapy. Phase IIB/TOC trials can be used to The next product to enter efficacy These challenges may be most eliminate unsuccessful vaccine candidates testing was a prime-boost strategy using a appropriately addressed by the selective from further evaluation relatively early canarypox vector (vCP 1521), followed use of Phase IIB or “test of concept” in the development process, or to build by an rgp120 boost (AIDSVAX B/E’). (TOC) trial designs. By definition, Phase upon successful vaccine prototypes. For The canarypox product generates a IIB/TOC trials are designed to accrue example, Merck evaluated a monovalent CD8+ cytotoxic T-lymphocyte (CTL) fewer endpoints than Phase III trials, human papillomavirus (HPV) vaccine response in approximately 25 percent of and can generally be completed more prototype with a Phase IIB/TOC trial prior recipients [10], and trial investigators quickly or with fewer resources than a to evaluating a quadravalent vaccine hope that, in combination with the

HIV VACCINE EFFICACY EVALUATION 53 CD4+ T-lymphocyte and antibody (e.g., lower bound of the 95 percent con­ effective antiretroviral therapy [15, 16], responses generated by the AIDSVAX fidence interval (CI) greater than 0 per­ and that duration has been extended B/E’ vaccine, this prime-boost approach cent) and can thus be smaller in sample considerably through early access to will protect against HIV acquisition. size. Phase IIB/TOC trials can also define antiretroviral therapy [17, 18]. Scientific opinion remains divided about appropriate trial endpoints and popula­ Antiretroviral therapy is also making a the likelihood of success of this vaccine tions for Phase III trials, and identify difference in the developing world, approach [11, 12]. The trial has fully potential immune correlates of protection. where untreated HIV infection may enrolled 16,000 volunteers, and trial Details of the collaborative Merck/HVTN progress to AIDS more rapidly [19, 20]. duration is anticipated to be more than trial Phase IIB/TOC trial, named the As global access to antiretroviral therapy five years. STEP study, will be provided throughout becomes an increasingly achievable (and A newer vaccine candidate has this article to illustrate the potential utility important) public health goal, the rele­ proven substantially more immunogenic of the Phase IIB/TOC approach. vant research question for CTL-based than the canarypox vaccines in Phase I HIV vaccines becomes whether such and II testing, and has also moved into Appropriate Trial Endpoints vaccines can delay the onset of need for efficacy evaluation. Merck has developed If a vaccine candidate is designed to pre­ antiretroviral therapy, rather than the several generations of replication- vent HIV acquisition, measurement of more traditional endpoint of clinical incompetent adenoviral vector HIV that trial endpoint is relatively straight­ AIDS diagnosis or death. Surrogate vaccines. The trivalent adenovirus type 5 forward. Serologic assays licensed by the measures of clinical progression are (Ad5) vaccine (MRKAd5 HIV-1 gag/pol/ U.S. Food and Drug Administration needed to ensure more rapid assessment nef) was well tolerated at the 1.5 x 1010 (FDA) can generally be used to differen­ of vaccine effects [6]. viral particle dose, and generated cellular tiate vaccine-induced antibody from Early measures of plasma viral load immune responses in more than three- true HIV infection, and these tests can and CD4+ T-cell counts have prognostic fourths of individuals with low pre­ be supplemented by assays to detect viral significance for later HIV disease pro­ existing Ad5 neutralizing antibody nucleic acid sequences. Experienced, gression and survival, and both factor (Nab) titers, and in more than half of independent investigators can be assem­ into recommendations for antiretroviral persons with high pre-existing Ad5 Nab bled to review assay results and adjudicate treatment [21]. Viral load has been use­ titers [13]. Rather than move this product endpoint determinations while remaining ful as an early surrogate marker of clinical directly into a Phase III trial, investigators blinded to study assignment. disease progression in antiretroviral from Merck and the National Institute of However, the current generation of treatment trials, and has served as the Allergy and Infectious Diseases (NIAID)­ viral vector vaccines is designed to gener­ basis for licensure decisions. If viral load sponsored HIV Vaccine Trials Network ate a robust CD8+ CTL response, with measures are taken early after peak (HVTN) opted to develop a collaborative no substantial ability to generate Nab viremia but before antiretroviral therapy Phase IIB/TOC trial. The rationale for against HIV primary isolates. Because is likely to be initiated—for example, getting data from Phase IIB/TOC trials CTLs are active only after productive within three months of detection of HIV first, before moving to Phase III trials, HIV infection has occurred, investigators infection—such measures are also unlikely was to obtain preliminary data on the believe that these vaccines are more to be confounded by early initiation of plausibility that this approach will be likely to control viral replication than antiretroviral therapy. In addition, such successful, both for this specific vaccine provide sterilizing immunity, although a measure could provide important sur­ candidate, and for other adenoviral vector both outcomes will be important to rogate information on the potential prototypes that have also entered the measure. The challenge in measuring impact of vaccine on secondary HIV clinical trial pipeline [14]. Unlike Phase clinical endpoints is the long latency transmission rates, as pre-treatment viral III trials that are designed to show public period between HIV acquisition and load has been shown to be strongly asso­ health utility (e.g., minimum 30 percent development of clinical disease. The ciated with the risk of HIV transmission protection from acquisition), Phase median time from HIV acquisition to in serodiscordant partner studies [22, IIB/TOC trials are designed to identify AIDS in the developed world was 8 to 10 23]. Direct measurement of the impact whether a product shows any promise years prior to the introduction of highly of vaccine on secondary transmission,

54 THE JORDAN REPORT 2007 on the other hand, will likely be chal­ study has two co-primary endpoints: Appropriate Populations for lenging and require cluster randomized HIV acquisition and post-infection viral Testing Vaccines controlled trials [24] or recruitment of load. The sample size for STEP is driven Vaccine efficacy may differ in different HIV-negative partners of infected volun­ largely by acquisition endpoint, rather populations, based on the mix in the teers [25]. Such studies would only be than the viral load endpoint. For example, trial population of age, gender, route of undertaken if earlier trials demonstrate the trial is powered to identify only sub­ HIV exposure, host genetics, circulating the plausibility of vaccine effects on stantial (i.e., greater than or equal to 50 viral subtype, pre-existing immunity to transmission through persistent reduc­ percent) reduction in HIV acquisition the viral vector used in the vaccine, or tion in HIV viral load among infected rates. This sample size also provides other environmental factors (e.g., nutri­ vaccinees. power to identify relatively modest (i.e., tion, co-infections). To limit the potential

To measure the durability of vaccine greater than or equal to 0.7 log10) reduc­ for confounding as a result of any of responses, later time points post-infection tion in early HIV viral load. It is not yet these factors, early efficacy trials may should also be measured and compared, clear how the FDA and other national best be conducted in relatively homoge­ in a blinded fashion, between vaccine and regulatory bodies will view surrogate neous populations. For example, the placebo recipients. Because of the potential measures of disease progression in licen­ STEP study is being conducted in popu­ for confounding by early initiation of sure decisions. To provide compelling lations at highest risk for clade B infection antiretroviral therapy, a composite end­ evidence of public health benefit, how in the Americas and Australia: men who point might be chosen to include initiation large a reduction in viral load would be have sex with men [28], with a smaller of antiretroviral therapy or reaching a required for how long a period of time? population of heterosexually exposed CD4+ T-cell count or viral load for Will benefits also be required to be seen women and men. Because preclinical and which antiretroviral therapy is recom­ in CD4+ T-cell counts and time to initi­ clinical data suggested that pre-existing mended [26, 27]. Other strategies may ation of antiretroviral therapy? Data neutralizing antibody to Ad5 could be useful in the analysis of post-infection generated from this trial should be quite attenuate vaccine-induced immune endpoints, to minimize the risk of intro­ helpful in making decisions about responses, the initial trial was limited to ducing bias from evaluating only the whether to take this product and other persons with low pre-existing Ad5 titers. subset of volunteers who become HIV- products with similar immunologic pro­ When Phase I data became available that infected. For example, if the vaccine files forward into Phase III testing. The demonstrated substantial immune were to protect against less virulent results will also provide useful concrete responses in the subgroup of participants quasi-species but not against those that data for discussions with regulatory with high pre-existing Ad5 titers, the cause rapid disease progression, analyses agencies about specific Phase III trial STEP study was expanded to include a comparing only the subset of infected endpoints and goals for ultimate licen­ stratum of high-risk volunteers with trial volunteers (excluding those protected sure. If the HIV acquisition endpoint is high pre-existing Ad5 titers. A follow-up from less virulent quasispecies) to the not met, future studies of this particular Phase IIB/TOC trial (HVTN 503) is entire group of infected placebo recipients vaccine candidate may focus more being planned with the same product in would lead to the erroneous conclusion appropriately on surrogate markers of South Africa, an area with a substantial that the vaccine enhanced disease pro­ disease progression. On extended follow- clade C epidemic. Although this candi­ gression. Some analyses might include up of infected trial participants, this date vaccine was created using clade B the entire population of vaccine and study will also provide data on the rate sequence isolates, the antigens included placebo recipients to ensure that overall of development of clinical endpoints, in the product are relatively conserved disease (or surrogate markers of disease) composite endpoints, and the relationship across clades, and induce immune incidence is compared between the entire of surrogate markers to clinical disease responses with cross-clade reactivity randomized population [6]. (e.g., AIDS and survival) that will be among HIV-infected individuals [29, 30] All three of the Phase III HIV vac­ useful ultimately for validation of surro­ and vaccinees [31]. The HVTN 503 cine trials launched to date have used gate markers. Phase IIB/TOC will evaluate the impact HIV acquisition as the only primary of clade on efficacy and provide guidance efficacy outcome variable. The STEP on the degree to which vaccine antigens

HIV VACCINE EFFICACY EVALUATION 55 need to match circulating strains. Immune Correlates of ing that the product should be reformu­ HVTN 503 will also evaluate vaccine Protection lated or discarded before proceeding to efficacy in a population of heterosexually Identification of vaccine-induced Phase III testing. In that situation, Phase exposed volunteers, including a large immune correlates of protection could IIB/TOC trials are both time- and cost- population of women, while the STEP help move HIV vaccine science forward effective compared with having moved study will largely comprise men who immeasurably, by providing qualitative directly from Phase II to Phase III testing have sex with men. Data combined from and quantitative targets for vaccine of an unsuccessful vaccine candidate. the two Phase IIB/TOC trials will allow design and development. Phase IIB/TOC If a Phase IIB/TOC trial demonstrates a measure of the robustness of protection trials can provide substantial power to sufficient efficacy to warrant that the provided by the vaccine, and will direct measure potential immune correlates of product proceeds to Phase III testing, future trials to appropriate populations protection, particularly for continuous decisions will need to be made about the based on pre-existing Ad5 titer, gender, outcomes, such as plasma viral load. For appropriate next steps for licensure of route of exposure, and viral subtype. example, in the low Ad5 titer stratum the product. In this situation, the Phase There is also considerable uncertainty alone, the STEP study is powered to IIB/TOC trial could either have accelerated in projecting HIV seroincidence in trial detect 0.25 log10 difference or greater in or slowed down the timeline for product populations. Risk generally declines in plasma viral load between those with development, depending on what is HIV vaccine trials [32], as participants high versus low immune response to the learned from the Phase IIB/TOC trial. receive regular risk reduction counseling, vaccine, if at least 30 percent of partici­ For example, if the Phase IIB/TOC trials and through other cohort effects such as pants develop that immune response are able to rule out (or in) a particular early infection of those who are most (e.g., positive ELISpot response). population, make large corrections in susceptible or most highly exposed. Other Considerably more power is available if anticipated seroincidence rates, provide population-level factors may affect the low and high Ad5 titer strata can be critical data for use of surrogate markers seroincidence during trials, such as pooled, or if data can be pooled across in trials, or identify potential immune widespread use of antiretroviral therapy the STEP study and HVTN 503. correlates of protection earlier than a among HIV-infected persons, or rollout However, there is very limited power to Phase III trial, then such trials can still be of other effective prevention strategies. evaluate any but the strongest correlates cost- and/or time-saving for that vaccine Because the power of efficacy trials is of protection from HIV acquisition, as candidate or for others following in the driven by the number of anticipated this would require a substantially greater clinical trials pipeline. However, it is also endpoints, accurate projection of seroin­ trial sample size. possible for Phase IIB/TOC trials to cidence is critical to ensure adequate slow down the development timeline of power and efficient use of resources. Sequencing Efficacy Trials successful vaccines, by inserting this One way to deal with this uncertainty is Phase IIB/TOC trials can provide intermediate step between immunogenicity to create endpoint-driven studies, in important preliminary information on and efficacy studies. To minimize such which the total number of endpoints the promise of a given vaccine candidate potential delays, it is important to create drives the timeline for interim and final and provide additional data in support a development pathway through licensure evaluation of trial results, rather than of specific surrogate markers and use of that weighs the appropriate timing of setting a pre-defined duration of study appropriate populations. But a single each step in the development process. follow-up. Both the STEP study and Phase IIB/TOC trial is not of sufficient Plans for evaluating the Merck HVTN 503 trials are endpoint-driven size or duration to qualify a product for MRKAd5 gag/pol/nef product can trials. In addition, both will provide licensure. How does use of Phase serve as a useful example of how such important data on current HIV seroinci­ IIB/TOC trials affect overall product sequencing can occur to minimize dence rates in trial populations that will be development timelines? potential delays in the development helpful in planning future Phase III trials. If a Phase IIB/TOC trial can show timeline. The STEP study expanded to that a vaccine product does not meet a include a high-Ad5 stratum before data minimum threshold of efficacy, the trial were available on the efficacy in the low will have been “successful” in determin­ Ad5 stratum for two reasons: (1) clinical

56 THE JORDAN REPORT 2007 data were available from Phase I trials suggesting similar immunogenicity in the two strata between these products, and (2) the majority of individuals in developing countries have high Ad5 titers, making testing the vaccine in this population of critical importance. Plans were then initiated for a parallel Phase IIB/TOC trial of this vaccine can­ didate in South Africa (HVTN 503) before data were available from STEP, utilizing the same data and specimen collection time points and methods for the two trials. The rationale for expanding geographically again relies, in part, on early clinical data suggesting similar immunogenicity across populations, and on the cross-clade immune responses generated by this vaccine. It is also plausi­ ble that vaccines may more readily pro­ tect against heterosexual HIV transmission than homosexual trans­ mission, and/or that protection will be greater in women than men [33]. Thus, whether or not the STEP study shows some protective efficacy, it will be useful to also have data on vaccine efficacy in women and heterosexual populations in other regions of the world. Taken together, the STEP study and HVTN 503 trial have power similar to a single, small Phase III trial. However, conducting this series of Phase IIB/TOC trials provides important data on appropriate trial end­ points, populations, and correlates of protection that will be important in moving this and other vaccine candi­ dates into pivotal Phase III trials. HIV presents a unique set of chal­ lenges for vaccine development. The selective use of Phase IIB/TOC trials, appropriately timed to avoid delays in product development, may ultimately speed development of a safe and effec­ tive HIV vaccine.

HIV VACCINE EFFICACY EVALUATION 57 References men: an 11 year follow up study, BMJ 30. Gupta SB et al., Cross-clade reactivity of HIV- 1. Koutsky LA et al., A controlled trial of a 1990;301(6762):1183-1188. 1-specific T-cell responses in HIV-1-infected human papillomavirus type 16 vaccine, N Engl 16. Time from HIV-1 seroconversion to AIDS and individuals from Botswana and Cameroon, J Med 2002;347(21):1645-1651. death before widespread use of highly-active J Acquir Immune Defic Syndr 2006;42(2):135­ 2. Villa LL et al., Prophylactic quadrivalent antiretroviral therapy: a collaborative re­ 139. human papillomavirus (types 6, 11, 16, and analysis. Collaborative Group on AIDS 31. Casimiro D, Detailed characterization of the 18) L1 virus-like particle vaccine in young Incubation and HIV Survival including the cellular immune responses in healthy volun­ women: a randomised double-blind placebo- CASCADE EU Concerted Action. Concerted teers immunized with replication-defective controlled multicentre phase II efficacy trial, Action on SeroConversion to AIDS and Death adenovirus HIV vaccines, 12th Conference on Lancet Oncol 2005;6(5):271-278. in Europe, Lancet 2000;355(9210):1131-1137. Retroviruses and Opportunistic Infections, 3. Harper DM et al., Efficacy of a bivalent L1 17. Palella FJJ et al., Survival benefit of initiating Boston, MA, Feb. 22-25, 2005. virus-like particle vaccine in prevention of antiretroviral therapy in HIV-infected persons 32. Bartholow BN et al., HIV sexual risk behavior infection with human papillomavirus types 16 in different CD4+ cell strata, Ann Intern Med over 36 months of follow-up in the world’s and 18 in young women: a randomised con­ 2003;138(8):620-626. first HIV vaccine efficacy trial, J Acquir trolled trial, Lancet 2004;364(9447):1757­ 18. Vittinghoff E et al., Combination antiretrovi­ Immune Defic Syndr 2005;39(1):90-101. 1765. ral therapy and recent declines in AIDS inci­ 33. Stanberry LR et al., Glycoprotein-D-adjuvant 4. Skjeldestad FE, FUTURE II steering commit­ dence and mortality, J Infect Dis 1999;179(3): vaccine to prevent genital herpes, N Engl J tee, Prophylactic quadrivalent human papillo­ 717-720. Med 2002;347(21):1652-1661. mavirus (HPV) (types 6, 11, 16, 18) L1 19. Jaffar S et al., The natural history of HIV-1 virus-like particle (VLP) vaccine and HIV-2 infections in adults in Africa: a lit­ (GardasilTM) reduces cervical intraepithelial erature review, Bull World Health Organ neoplasia (CIN) 2/3 risk, Infectious Disease 2004;82(6):462-469. Society of America 43rd Annual Meeting,San 20. Rangsin R et al., The natural history of HIV-1 Francisco, CA 2005. infection in young Thai men after seroconver­ 5. Harper DM et al., Sustained efficacy up to 4.5 sion, J Acquir Immune Defic Syndr 2004;36(1): years of a bivalent L1 virus-like particle vac­ 622-629. cine against human papillomavirus types 16 21. DHHS Panel on Antiretroviral Guidelines for and 18: follow-up from a randomised control Adults and Adolescents, Guidelines for the use trial, Lancet 2006;367(9518):1247-1255. of antiretroviral agents in HIV-1-infected 6. Gilbert PB et al., Correlation between adults and adolescents. In: immunologic responses to a recombinant gly­ http://AIDSinfo.nih.gov (direct link: coprotein 120 vaccine and incidence of HIV-1 http://aidsinfo.nih.gov/ContentFiles/Adultand infection in a phase 3 HIV-1 preventive vac­ AdolescentGL.pdf) . cine trial, J Infect Dis 2005;191(5):666-677. 22. Quinn TC et al., Viral load and heterosexual 7. The rgp120 HIV Vaccine Study Group, transmission of human immunodeficiency Placebo-controlled phase 3 trial of recombi­ virus type 1, Rakai Project Study Group, nant glycoprotein 120 vaccine to prevent HIV­ N Engl J Med 2000;342(13):921-929. 1 infection, J Infect Dis 2005;191(5):654-665. 23. Gray RH et al., Probability of HIV-1 transmis­ 8. Graham BS and Mascola JR, Lessons from fail­ sion per coital act in monogamous, heterosex­ ure—preparing for future HIV-1 vaccine effi­ ual, HIV-1-discordant couples in Rakai, cacy trials, J Infect Dis 2005;191(5):647-649. Uganda, Lancet 2001;357(9263):1149-1153. 9. Pitisuttithum P, Efficacy of AIDSVAX B/E vac­ 24. Hayes RJ et al., Design and analysis issues in cine in injecting drug users, 11th Conference cluster-randomized trials of interventions on Retroviruses and Opportunistic Infections, against infectious diseases, Stat Methods Med San Francisco, CA, Feb. 8-11, 2004. Res 2000;9(2):95-116. 10. Nitayaphan S et al., Safety and immunogenic­ 25. Halloran ME et al., Study designs for evaluat­ ity of an HIV subtype B and E prime-boost ing different efficacy and effectiveness aspects vaccine combination in HIV-negative Thai of vaccines, Am J Epidemiol 1997;146(10):789­ adults, J Infect Dis 2004;190(4):702-706. 803. 11. Burton DR et al., Public health. A sound 26. Gilbert PB and Sun Y, Failure time analysis of rationale needed for phase III HIV-1 vaccine HIV vaccine effects on viral load and anti­ trials, Science 2004;303(5656):316. retroviral therapy initiation, Biostatistics 12. McNeil JG et al., Policy rebuttal. HIV vaccine 2005;6(3):374-394. trial justified, Science 2004;303(5660):961. 27. Hudgens MG et al., On the analysis of viral 13. Priddy F et al., Safety and immunogenicity of load endpoints in HIV vaccine trials, Stat Med the MRK Adenovirus Type-5 gag/pol/nef HIV­ 2003;22(14):2281-2298. 1 (Trivalent) vaccine in healthy adults, (#135), 28. 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58 THE JORDAN REPORT 2007 Susan P. Buchbinder, M.D. Dr. Buchbinder is Director of the HIV Research Section of the San Francisco Department of Public Health. She chairs the Efficacy Trials Design Working Group for the HIV Vaccine Trials Network (HVTN), and chairs the collaborative Merck/HVTN test of concept vaccine efficacy trial (STEP Study) with her col­ league from Merck, Dr. Michael Robertson. In preparation for efficacy trials, she has served as Associate Director for Site Expansion in the Americas for the HVTN, working with colleagues studying clade B epidemics to identify high-risk cohorts of women. Dr. Buchbinder also serves on the AIDS Vaccine Research Working Group and AIDS Research Advisory Council for the National Institute of Allergy and Infectious Diseases. Dr. Buchbinder began her research career in the study of HIV long-term non-progressors in the San Francisco City Clinic Cohort Study. In addition to her continued interest in long-term non-progressors and highly exposed, uninfected persons, her current research focuses on evaluating risk factors for HIV infection and evaluating HIV prevention strategies including HIV vaccines, anti­ retrovirals for HIV-negative persons, treatment of sexually transmitted infec­ tions, microbicides, and behavioral interventions.

HIV VACCINE EFFICACY EVALUATION 59

The Animal Rule from a Vaccine Development Perspective

Mark J. Abdy, D.V.M., Ph.D., Michael applied only when appropriate animal genicity data must still be generated Merchlinsky, Ph.D., and Drusilla L. model and study design criteria can be in traditional clinical studies [2]. For Burns, Ph.D. met that provide a solid scientific basis vaccines, these clinical studies will also for extrapolation of efficacy from animals serve as the means to collect immune he threat of biological weapons to humans. response data from vaccinated humans has stimulated the development Despite its commonly referred to that may allow for making comparison T of a number of new vaccines to name, a search for the Animal Rule in between animal and human studies, and prevent diseases such as smallpox, anthrax, the Code of Federal Regulations [CFR] ultimately bridging of immune response Ebola, and plague—diseases which will yield negative results. The relevant data between the species. heretofore either have been eradicated regulations are published in two locations or occur at a very low incidence in the in the CFR, namely 21 CFR§601.90-95 Requirements for Animal human population. As for any vaccine, [Biologicals], “Approval of Biological Vaccine Studies these products must be demonstrated to Products When Human Efficacy Studies Under the Animal Rule, animal data can be both safe and effective before they are Not Ethical or Feasible,” and 21 be used to provide evidence of efficacy can be approved for use by the U.S. CFR§314.600-650 [Drugs], “Approval of of a vaccine only if all of the following Food and Drug Administration (FDA). Drug Products When Human Efficacy four criteria are met: Safety of such vaccines can be evaluated Studies are Not Ethical or Feasible.” (1) There is a reasonably well understood in Phase I, II, and III clinical trials. To date, the Center for Biologics pathophysiological mechanism of However, the efficacy of many of these Evaluation and Research (CBER) has toxicity of the substance and its pre­ vaccines cannot be assessed in clinical not approved any products under this vention or substantial reduction by field trials due to the epidemiology of rule. The sole product currently approved the product; the respective diseases, and human chal­ by FDA using the rule is pyridostigmine (2) The effect is demonstrated in more lenge studies cannot be conducted because bromide, a drug regulated by the Center than one animal species expected to it would be unethical to deliberately for Drug Evaluation and Research (CDER) react with a response predictive for expose volunteers to life-threatening that increases survival after exposure to humans, unless the effect is demon­ infectious agents. In response to this the nerve agent Soman. The scope of the strated in a single animal species that problem, FDA issued a new rule in May Animal Rule is broad and may be applied represents a sufficiently well-charac­ 2002 entitled “New Drug and Biological to any drug or vaccine that can ameliorate terized animal model for predicting Drug Products; Evidence Needed to or prevent serious or life-threatening the response in humans; Demonstrate Effectiveness of New Drugs conditions caused by exposure to lethal (3) The animal study endpoint is clearly When Human Efficacy Studies Are Not or permanently disabling chemical, related to the desired benefit in Ethical or Feasible.” [1]. biological, radiological, and nuclear humans, generally the enhancement This rule, commonly referred to as substances. Thus, the scope is not limited of survival or prevention of major the “Animal Rule,” allows appropriate to products related to counterterrorism. morbidity; and studies in animals to provide evidence of Importantly, the rule does not apply if (4) The data or information on the efficacy for new drug and biological the drug or vaccine can be licensed kinetics and pharmacodynamics of products, such as vaccines, in certain using standards described elsewhere in the product or other relevant data or specific cases. The rule can apply only the FDA regulations. The Animal Rule information, in animals and humans, when human efficacy studies are not does not represent a shortcut to licensure. allows selection of an effective dose feasible or ethical. Moreover, the rule is Moreover, human safety and immuno­ in humans.

THE ANIMAL RULE 61 These conditions can only be met when The scientific validity of the extrapolation the mechanism of action of anthrax well-designed and well-controlled ani­ will be considered by FDA scientists, toxin, and the role of toxin-neutralizing mal studies are conducted. A number of expert panels such as FDA Advisory antibodies (TNAs) in protection against factors should be taken into account Committees, and the general scientific disease satisfies the first criterion of the when designing these studies, including and medical communities. Animal Rule. Moreover, the role of the expected route of exposure to the Because study design will depend on TNAs in protection against disease pro­ biological agent, expected exposure vaccine type and indication, it is not vides a basis for use of TNA levels as a dose, and the vaccine indication (e.g., possible here to provide specifics for a measure of protective response [9, 10]. pre-exposure prophylaxis, post-exposure study design that can be applied generally. When designing the anthrax vaccine prophylaxis). Importantly, the animal However, we would like to present animal studies, one of the first questions species used in the studies should be examples of two vaccines that illustrate that had to be addressed was which ani­ those in which the animal disease mim­ the types of thought processes used to mal species should be used. The two ics that of humans as closely as possible. design studies that are expected to fulfill animal species currently regarded as the In addition to the requirements that the four criteria of the Animal Rule in a most appropriate for use are the rhesus have been discussed, a number of post- scientifically rigorous manner. macaque (Macaca mulatta) and the New marketing and post-event requirements Zealand White rabbit based upon the exist for approval of a product using the New Generation Anthrax Vaccines resemblance of the pathology of experi­ Animal Rule [1]. New generation anthrax vaccines are mental anthrax in these animals to that currently being developed, e.g., vaccines of human disease [5, 3, 11]. A second Animal Study Designs to composed of a recombinant form of a consideration was animal study endpoint. Support Vaccine Licensure Bacillus anthracis protein known as pro­ Because anthrax is generally a lethal dis­ Each different type of vaccine (e.g., tective antigen (rPA). The choice of this ease, survival after challenge with B. anthrax, smallpox, plague, Ebola) and protein was based on knowledge of B. anthracis is considered to be an appro­ vaccine indication will require specialized anthracis pathogenesis, which has been priate endpoint. Additionally, the vaccine animal model development and study studied extensively. Studies have shown indication must be considered. Since design. The rule does not state which that upon inhalation of B. anthracis into anthrax vaccines might be used for animal species or strain(s) should be the lungs, the spores are engulfed by either pre- or post-exposure prophylaxis, used for evaluation of any given vaccine. alveolar macrophages. During transit of the studies should be designed to reflect Thus a vaccine manufacturer can develop the macrophages to the lymph nodes, the desired clinical indication, i.e., chal­ an animal model of its choosing that the spores germinate. Vegetative bacteria lenge of the animals with B. anthracis meets the aforementioned four criteria. are eventually released into the blood­ should occur post-vaccination if a pre- The choice of each model will need to stream where they produce copious exposure indication is being sought and be justified to CBER’s Office of Vaccines quantities of anthrax toxin, a tri-partite pre-vaccination for a post-exposure Research and Review (OVRR). Data in toxin composed of a binding component, indication. The challenge strain and the the existing scientific literature can help protective antigen, and two enzymatically challenge dose must be carefully consid­ serve as the basis for animal study design. active components, lethal factor and ered, should be relevant, and the choice (For example, see references [3, 4].) In edema factor. The resulting toxemia is should be discussed with CBER before addition, workshops such as those held thought to result in the clinical manifes­ initiation of an animal efficacy study. on this topic for anthrax and plague tations of the disease. (For reviews of B. These considerations addressed the sec­ vaccines [5, 6] have provided valuable anthracis pathogenesis and anthrax ond and third animal study criteria of scientific consensus on the appropriate toxin, see [7, 8].) Thus, neutralization of the rule. design of studies. The design of any animal the toxin by antibodies induced by Perhaps the most complex aspect of study conducted to support efficacy of a immunization with rPA vaccines would the Animal Rule to fulfill is the fourth vaccine in humans must include a scien­ be expected to prevent disease. The sig­ criterion that efficacy data should be tifically sound basis for extrapolating nificant body of knowledge available extrapolated from animals to humans in data from the animal study to humans. concerning pathogenicity of B. anthracis, a scientifically valid and rigorous manner.

62 THE JORDAN REPORT 2007 In the case of rPA anthrax vaccines, developed. Clinically, smallpox spreads pathogenesis and the immune response. TNA titers induced by the vaccine will from person to person via the oropha­ Mice are susceptible to only a few likely be the “common language” that ryngeal route. Following a 7- to 17-day plaque-forming units of ectromelia can be used to translate a protective incubation period, the disease manifests as virus, or mousepox, and moderate doses immune response in animals to that of a disseminated viral infection with high of cowpox virus or vaccinia virus strain humans, although additional data are fever and a pustular rash that spreads Western Reserve (WR). Additionally, needed to confirm this. If this is found over the body [13]. However, there is most of the challenge experiments using to be the case, then extrapolation of still no consensus as to the actual cause cowpox and vaccinia have used respira­ protection data from animals to efficacy of death from smallpox in humans, thus tory routes of virus challenge. Many of in humans may be possible. First, TNA complicating the ability to meet the first the components of the humoral and cel­ titers in vaccinated animals protected animal study criterion of the rule. lular immune response to vaccination from challenge with B. anthracis could Each of the current animal models and the basis for resistance to orthopox be used to estimate the level of TNA used for evaluation of smallpox vaccines virus infection have been studied in required for protection in the animal. presents specific strengths and weaknesses. mice. More recently, the disease caused This level could be compared to that The lack of well-characterized animal by rabbitpox virus in New Zealand achieved upon vaccination of humans in models that fully mimic a smallpox White rabbits has been studied as a clinical immunogenicity trials. From this infection in humans means that the model for smallpox in humans. information, efficacy of the vaccine at evaluation of a new generation smallpox Rabbitpox infection produces a relatively the dose and schedule administered in vaccine under the auspices of the large amount of extracellular enveloped humans might be inferred. Animal Rule will require a combination virus (EEV) when compared to other of animal models to provide a measure orthopoxviruses, making it a more strin­ New Generation Smallpox Vaccines of confidence in the efficacy of the vac­ gent model for virus spread within an Certain new generation smallpox vaccines cine to protect against severe disease or infected host. Most recently, a number may need to use the Animal Rule as a to prevent virus entry and/or spread. of laboratories have pursued the devel­ regulatory pathway to approval [12]. OVRR has indicated that, if feasible, the opment of a non-human primate model The Animal Rule criteria for a new gen­ animal challenge studies should use the in cynomolgus macaques [14, 15]. In this eration (attenuated) smallpox vaccine, route of exposure that best mimics the model, monkeys are challenged with a such as a modified vaccinia Ankara anticipated natural route of exposure. lethal dose of the Zaire strain of mon­ (MVA) vaccine, are more challenging The primary endpoint of the animal keypox virus that is known to cause than those described for the new genera­ efficacy studies should be protection by fatalities in humans. While other monkey tion anthrax vaccines. Since variola virus the candidate vaccine against lethal chal­ species have been used in orthopoxvirus has no identified animal reservoir and lenge with two relevant pathogenic research, the demand and supply dictate smallpox is not considered a zoonotic orthopoxviruses in at least two mam­ that cynomologus monkeys be used disease, there are no natural animal malian species. Presently, most research most often today. In the future, other models for variola. Secondly, since the has been focused on the development of alternatives may exist, as research is con­ disease was eradicated from the human suitable animal models using mice, rab­ tinuing in the development of animal population almost 30 years ago, not bits, and cynomolgus macaques (Macaca models for vaccine evaluation. enough is known about the pathophysi­ fascicularis). Each of these models comes The evaluation of vaccines using ology and pathogenesis of smallpox with its own set of challenges, including smallpox (Variola major) is complicated infection in people. The correlates of small sample size, perfecting the respira­ by the restriction of research using live immunity and the mechanism of tory challenge, working in biosafety level variola virus to two BSL-4, World Health immune protection are not fully under­ (BSL)-3 and -4 laboratories, and cost. Organization-sanctioned facilities, stood, and animal models mimicking the The BALB/c strain of mice is the namely at the Centers for Disease natural respiratory exposure route for most commonly used mouse model in Control and Prevention in Atlanta and human infection, and in particular a non­ orthopoxvirus research and is best Russia’s State Research Center of human primate model, have not been understood with regard to disease Virology and Biotechnology (VECTOR).

THE ANIMAL RULE 63 Although smallpox infections in cynomol­ with Dryvax is associated with a broad rule pertains only to efficacy data. Vaccine gus monkeys were recently reported humoral and cellular immune response. immunogenicity and safety data will need [16], this model used an extremely high The immunological investigation of new to be generated in human clinical trials. challenge dose, had an atypical disease smallpox vaccines will use a combination course, is exploratory, and is not available of immunological assays, some still under­ to the wider orthopoxvirus research going validation. These assays will likely community. At present, OVRR does not include Plaque Reduction Neutralizing require a demonstration of efficacy in a Titers (PRNT), ELISA anti-vaccinia variola virus animal model for evalua­ antibody levels, and ELISPOT assays for tion of a smallpox vaccine. However, the cell-mediated response. One reason companies pursuing the approval of new for fully characterizing the immune smallpox vaccines can use Wyeth response to vaccination will be to compare Dryvax, an effective, approved smallpox the response elicited by new vaccines to vaccine, as a comparator. The ability of the immune response induced by the candidate vaccine to protect against Dryvax used in the same animal model, lethal orthopox virus challenge and to thus enabling comparison to a vaccine elicit an immune response in animal with known efficacy against smallpox. models and humans can be compared to Dryvax. This will be important in meet­ Summary and Conclusions ing the fourth animal study criterion of The development of vaccines for most bio­ the rule. threat agents and some emerging diseases The animal efficacy studies should presents unique challenges for clinical use appropriate orthopoxviruses—those development and licensure. The worldwide closely related to smallpox virus—and incidence of natural disease caused by challenge doses that induce clinical disease many of these agents is usually low, so that best mimics human smallpox disease, classical field trials are not feasible. This, including the normal route of exposure. along with the fact that it is unethical to These viruses could include ectromelia conduct human challenge studies for most virus, cowpox virus (Brighton strain), of these agents, makes direct demonstra­ vaccinia virus (WR strain), rabbitpox tion of efficacy in humans virtually virus, and monkeypox virus, depending impossible. That problem precluded the on the susceptible animal species. The licensure of vaccines for such infectious appropriate challenge dose will be agents prior to the Animal Rule going dependent on the individual circumstance, into effect. The Animal Rule can address since the species of animal to be chal­ this problem and provides an avenue to lenged, route of challenge, and type of vaccine licensure, provided that the four- virus are all variables. animal study criteria of the Animal Rule The final animal study criterion of can be fulfilled in a scientifically sound the rule is to allow for the selection of and rigorous manner. However, it is an effective human dose and vaccine important to note that the Animal Rule schedule. This will require bridging does not specify which species should be between the animal and human immune used for a specific situation, and thus any response data. Although we do not cur­ animal model may be used as long as it rently know the critical correlates of the rigorously meets the four critical require­ protective immune response, vaccination ments previously discussed. Finally, the

64 THE JORDAN REPORT 2007 References 1. Food and Drug Administration, HHS, New drug and biological products; evidence needed to demonstrate effectiveness of new drugs when human efficacy studies are not ethical or feasible, Federal Register 2002; 67:37988­ 37998. 2. Horne AD et al., Preventive vaccines against bioterrorism: evaluation of efficacy and safety, Vaccine 2004;23:84-90. 3. Fritz DL et al., Pathology of experimental inhalation anthrax in the rhesus monkey, Lab Invest 1995;73:691-702. 4. Geisbert TW et al., Pathogenesis of Ebola hemorrhagic fever in cynomolgus macaques: evidence that dendritic cells are early and sus­ tained targets of infection, Am J Pathol 2003;163:2347-2370. 5. Food and Drug Administration, Transcripts of Workshop, Anthrax Vaccines: Efficacy Testing and Surrogate Markers of Immunity, Bethesda, MD, 2002. 6. Food and Drug Administration, Transcripts of Workshop, Animal Models and Correlates of Protection for Plague Vaccines, Gaithersburg, MD, 2004. 7. Dixon TC et al., Anthrax, N Engl J Med 1999;341:815-826. 8. Mourez M et al., 2001: A year of major advances in anthrax toxin research, Trends in Microbiol 2002;10:287-293. 9. Pitt ML, In vitro correlate of immunity in a rabbit model of inhalation anthrax, Vaccine 2001;19:4768-4773. 10. Weiss S et al., Immunological correlates of protection against intranasal challenge of Bacillus anthracis spores conferred by a pro­ tective antigen-based vaccine in rabbits, Infect Immun 2006;74:394-398. 11. Zaucha GM et al., The pathology of experi­ mental anthrax in rabbits exposed by inhala­ tion and subcutaneous inoculation, Arch Pathol Lab Med 1998;122:982-992. 12. Rosenthal SR et al., Developing new smallpox vaccines, Emerg Infect Dis 2001;7:920-926. 13. Breman JE and Henderson DA, Diagnosis and management of smallpox, N Engl J Med 2002; 346:1300-1308. 14. Earl PL et al., Immunogenicity of highly attenuated MVA smallpox vaccine and protec­ tion against smallpox, Nature 2004;428:182­ 185. 15. Stittelaar KJ et al., Modified vaccinia virus Ankara protects macaques against respiratory challenge with monkeypox virus, J Virol 2005;79:7845-7851. 16. Jahrling PB et al., Exploring the potential of variola virus infection of cynomolgus macaques as a model for human smallpox, Proc Natl Acad Sci USA 2004;101:15196­ 15200.

THE ANIMAL RULE 65 Mark J. Abdy, D.V.M., Ph.D. Michael Merchlinsky, Ph.D. Drusilla L. Burns, Ph.D. Dr. Abdy is a veterinary medical officer Dr. Merchlinsky is a Senior Investigator, Dr. Burns is Chief, Laboratory of Respi­ in the Center for Biologics Evaluation Laboratory of DNA Viruses, Division of ratory and Special Pathogens in the and Research (CBER), U.S. Food and Viral Products, Office of Vaccines Division of Bacterial, Parasitic, and Drug Administration. He graduated Research and Review, Center for Biolog­ Allergenic Products, Office of Vaccines from the University of Georgia College ics Evaluation and Research (CBER), U.S. Research and Review, Center for Biolog­ of Veterinary Medicine in 1992 and Food and Drug Administration. He ics Evaluation and Research (CBER), worked in a mixed animal veterinary joined CBER in 1995 after receiving a U.S. Food and Drug Administration. She practice in South Carolina. He then Ph. D. from Yale University in molecular joined CBER in 1984 after receiving her returned to the University of Georgia biophysics and biochemistry and com­ Ph.D. in biochemistry from the Univer­ and completed a veterinary anatomic pleting a post-doctoral fellowship at the sity of California, Berkeley and complet­ pathology residency and Ph.D. in veteri­ National Institutes of Health. He is a ing a post-doctoral fellowship at the nary pathology in 1997. Following grad­ principal investigator in the Laboratory National Institutes of Health. Her uate school, he joined the faculty at the of Poxvirus Biology with research focused research is in the area of microbial University of Florida College of on the development and evaluation of pathogenesis and includes studies on the Veterinary Medicine where he managed poxvirus vaccines. He also serves as the pathogenesis of Bacillus anthracis as well an equine influenza vaccine trial for primary product reviewer for many as host response to the bacteria. In addi­ three years. In 2000, he was selected as poxvirus-based vaccines. tion to her research activities, she is the American Veterinary Medical involved in the regulation of anthrax Association Congressional Science and other bacterial vaccines. Fellow and spent his fellowship year working on bioscience issues for Congressman Sherwood Boehlert. In September 2001, he was hired as a pro­ fessional staff member for the House Committee on Science where he worked primarily on public health issues for Chairman Boehlert. He joined the Office of Vaccines Research and Review in CBER in June 2002, and works pri­ marily on issues pertaining to the Animal Rule.

66 THE JORDAN REPORT 2007 VACCINE UPDATES 68 THE JORDAN REPORT 2007 Supporting the Nation’s Biodefense

Introduction In the wake of the 2001 terrorist difficult to deploy or less likely to cause attacks, the National Institutes of Health widespread harm than Category A agents). iological weapons present a (NIH) embarked on a systematic strate­ The Strategic Plan provides a blueprint unique threat because contagious gic biodefense planning process by for constructing three essential pillars of Bdiseases can spread rapidly convening the Blue Ribbon Panel on the biodefense research program: (1) basic beyond the area of initial outbreak with Bioterrorism and Its Implications for research on microbes and host immune potential to cause massive casualties and Biomedical Research, comprised of defenses, which serves as the foundation economic disruption. In 2001, the distinguished researchers representing for applied research; (2) targeted, mile- United States encountered bioterrorism academia, private industry, civilian stone-driven medical countermeasure in the deliberate exposure of the civilian government agencies, and the military. development to create the vaccines, population to anthrax spores hidden in Based on the panel’s recommendations therapeutics, and diagnostics that will be several pieces of mail delivered via the and extensive discussions with other crucial in the event of a bioterror attack; U.S. Postal Service. The anthrax attacks revealed a gap in the nation’s overall preparedness against bioterrorism. Other events, such as the first docu­ mented instance of avian influenza virus (H5N1) transmission from birds to humans in 1997, the arrival of West Nile virus in North America in 1999, and the emergence of severe acute respiratory syndrome (SARS) in China in 2002, highlight the continuing threat that emerging and re-emerging infectious diseases pose to public health. They illustrate the need for the federal gov­ ernment to be prepared to respond to potential infectious disease outbreaks caused either naturally or by deliberate The components of a smallpox vaccination kit including the diluent, vial of Dryvax smallpox vaccine, and a bifurcated needle. Courtesy of CDC / James Gathany release of pathogens. The National Institute of Allergy federal agencies, NIH developed three and (3) infrastructure needed to safely and Infectious Diseases (NIAID) is the key documents to guide its biodefense conduct research on dangerous lead agency within the U.S. Department research program: the NIAID Strategic pathogens. The Biodefense Research of Health and Human Services (HHS) Plan for Biodefense Research, the NIAID Agendas present detailed descriptions of for conducting research concerning Research Agenda for CDC Category A short-term, intermediate, and long-term potential agents of bioterrorism that Agents (covering agents that pose the goals for research on the wide variety of directly affect human health. NIAID’s gravest threat to human health, such as potential bioterrorism agents. long institutional experience with infec­ those that cause smallpox, anthrax, bot­ NIAID Category A agents represent tious disease research provided a foun­ ulism, and plague), and the NIAID the most dangerous threats. These dation for the seamless adoption of a Research Agenda for Category B and C pathogens, including smallpox and biodefense role that has expanded Priority Pathogens (for agents whose anthrax, are given the Institute’s highest greatly over the past five years. biological properties make them more priority because they (1) are easily dis-

SUPPORTING THE NATION’S BIODEFENSE 69 seminated or transmitted from technology (rPA) and combined person to person, (2) result in with aluminum adjuvant. The rPA high mortality rates with the vaccines have been tested for potential for major public safety and efficacy in rabbits and health impact, (3) would likely monkeys, and subsequently cause significant social disrup­ underwent clinical safety testing tion, and (4) require special in people. To date, large-scale action for public health pre- manufacturing capability of rPA paredness. vaccines has been demonstrated One of the key elements of and the vaccines appear to be safe the Institute’s research agenda for and immunogenic in people. Category A agents is developing medical One of the most promising countermeasures, including vaccines, approaches against smallpox is the therapeutics, and diagnostics, that can modified vaccinia Ankara (MVA) vaccine. protect the public in the event of a public Anthrax heptamer structure. Courtesy of John R. This vaccine is unable to grow in human health emergency. Vaccines play a crucial Collier, Harvard Medical School 2002 cells and cannot form a lesion at the site role in preparedness in that they prevent of vaccination, making it likely to be safe infection, and therefore have the potential leaving a significant portion of the U.S. for use in individuals who should not to maintain the vaccinated population’s population without access to immuniza­ receive Dryvax. NIAID-supported health in the midst of an outbreak. Below tion. researchers successfully performed small- are some examples of progress being made The anthrax vaccine currently scale manufacturing of the MVA vaccines in developing vaccines and vaccine strate­ licensed in the United States, BioThrax, and conducted small Phase I clinical trials gies for Category A priority agents. is a crude mixture that consists of filtered in healthy volunteers. These early develop­ Bacillus anthracis culture supernatant ment studies showed that MVA could be Current State of Science treated with formaldehyde and mixed manufactured in compliance with current Researchers Make Rapid Advances with an aluminum adjuvant. The vaccine laws and regulations, and that it in Vaccine Development includes a subunit of anthrax toxins appeared to be safe and immunogenic in The vaccine resources of the United called Protective Antigen (PA), which is healthy volunteers. States are far stronger than they were just known to generate an antibody response. Following these successes, large-scale five years ago. For example, in September A 2002 Institute of Medicine report manufacturing of MVA was performed 2001, the United States had only 15.4 mil­ entitled “The Anthrax Vaccine: Is It Safe? and Phase II clinical studies have been lion doses of smallpox vaccine available; Does It Work?” recommended that planned in both healthy individuals and today there are more than 300 million research be pursued and encouraged to those who are immunocompromised. doses, due in part to NIAID-supported develop other possible anthrax vaccine The purpose of these studies will be to clinical research on dose requirements of products that are less reactogenic than further assess the safety of these vaccines, older smallpox vaccines. BioThrax and can be produced more and begin to assess effectiveness based However, the vaccines currently consistently. on the immune response. Several of available are not without their faults. NIAID is supporting research on these clinical trials have started, including The smallpox vaccine currently used, next-generation vaccines against smallpox trials in volunteers with HIV. Dryvax, is highly efficacious, but is associ­ and anthrax that are not only safer and Additional progress in developing ated with significant local and/or sys­ more reliable, but may also be used by the new vaccines against Category A agents temic reaction in more than 90 percent of entire U.S. population, including those includes the first human clinical trial of vaccinees. In addition, Dryvax should not with compromised immune systems. For a DNA vaccine designed to prevent Ebola be given to individuals who are immuno­ anthrax, NIAID is supporting the devel­ infection. This recently completed trial compromised, such as those with opment of vaccines comprised of only was conducted by researchers at the human immunodeficiency virus (HIV), PA produced by modern recombinant Institute’s Dale and Betty Bumpers Vaccine

70 THE JORDAN REPORT 2007 Research Center (VRC). The vaccine, ment. However, this approach is especially dengue vaccine slated for clinical trial in composed of three DNA plasmids, was slow and difficult for dengue because of the near future. In addition, they continue well-tolerated and elicited both humoral the need to develop four different vaccine to create dengue viruses with novel and cellular immune responses at all viruses that must be assessed separately attenuating mutations for use in the doses. In parallel, non-human primate and in combination both in vitro and in event that ongoing clinical trials suggest clinical studies have refined the design animals before advancing to clinical tri­ that additional changes in the tetravalent of the Ebola vaccine products. The DNA als. Classic in vitro tests such as plaque formulation are needed. Each of the four plasmid product is currently being man­ reduction assays do not reliably predict components of NIAID’s dengue tetrava­ ufactured for clinical testing. the behavior of dengue viruses in animals, lent vaccine has a large, attenuating, and which in turn, are imperfect models of genetically stable 30-nucleotide deletion Novel Strategies Tackle Challenging dengue in humans. And often a single in its genome. Because chimerization is Pathogens serotype vaccine shows promise in clini­ also attenuating, the two chimeric NIAID researchers are also designing cal trials but fails when included in a viruses in this tetravalent vaccine are new strategies to tackle the complexities tetravalent vaccine as it competes with even more stable and less likely to revert of Category A agents. For example, the other three serotypes to stimulate back to non-attenuated forms, as well as developing a vaccine against dengue has immunity. less transmissible to mosquitoes. been extremely complicated due to the As with other live attenuated vaccines, NIAID’s chimerization methodology virus’ four subtypes. While infection success lies in making the viruses suffi­ has been licensed to Acambis, whose with one dengue serotype results in life­ ciently weak to be safe to administer yet tetravalent vaccine appears promising long immunity against that serotype, at still able to induce a protective immune in early clinical trials. NIAID is working best it provides only temporary cross-pro­ response. Two other qualities are impor­ with scientists in India and Brazil to tection against the others. Worse yet, tant in a dengue vaccine as well: the vac­ further dengue vaccine efforts in those subsequent infection with a different cine viruses should not be transmissible countries as well. Using different attenu­ dengue serotype can be much more to mosquitoes that bite a vaccinee, and ation techniques, investigators from severe, a phenomenon called antibody- the viruses should be cultivable to high titer Mahidol University in Thailand, Walter dependent disease enhancement in a cell line that permits cost-effective Reed scientists, and others continue (ADDE). Therefore, a dengue vaccine manufacturing. their long-term work toward development must be tetravalent and provide protection Dengue researchers have used several of a successful dengue vaccine. against all four dengue serotypes. methods to weaken the vaccine viruses, A second major impediment to including serial infection in cell cultures Basic Research Holds the Key for dengue vaccine development is the lack or animals and reverse genetics to intro­ New Countermeasures of an animal model of dengue that duce attenuating nucleotide deletions A key component of the NIAID biode­ mimics human disease. The effectiveness and point mutations. Chimerization, a fense research program is basic research of a vaccine candidate is inferred by the method developed by NIAID researchers to understand how pathogens interact levels of antibodies it induces and by in the early 1990s, also has been found with human hosts. Recognizing the sig­ determining the level of dengue wild-type to attenuate the viral hemorrhagic fever nificance of genomic sequencing to virus detected in the blood of vaccinated flaviviruses, such as dengue. Chimerization biodefense, NIAID-supported animals (vs. unvaccinated controls) follow­ involves replacing the genes of an atten­ researchers and their international col­ ing challenge with wild-type dengue virus. uated virus (the backbone or recipient leagues sequenced complete genomes of Researchers in the United States and virus) with those of another (the donor at least one strain of each Category A abroad have worked to develop a tetrava­ virus) to develop a third virus—a agent. This includes multiple strains of lent dengue vaccine for years. Most have chimera—that is attenuated but induces the anthrax bacterium. The Institute has used the live attenuated vaccine approach, immunity to the donor virus. also expanded its functional genomics which was used in the successful yellow NIAID researchers have used both program to provide comprehensive fever vaccine and is also the most eco­ recombinant DNA techniques and genomic, bioinformatic, and proteomic nomical method of vaccine develop­ chimerization to develop a tetravalent resources for basic and applied research

SUPPORTING THE NATION’S BIODEFENSE 71 to rapidly address the nation’s biode­ tularemia than systemic tularemia. countermeasures in the form of diagnos­ fense needs. These resources include the Understanding the host response to this tics, therapeutics, and vaccines, will Pathogen Functional Genomics highly virulent pathogen is a vital step help us cope with naturally emerging, Resource Center, Microbial Sequencing toward developing effective vaccines for re-emerging, and deliberately released Centers, Bioinformatics Resource Cen­ systemic and pulmonary manifestations microbes alike. ters, and Biodefense Proteomics of the disease. For more information about NIAID Research Centers. biodefense research, including research The human innate immune system Challenges and Opportunities agendas and progress reports, visit is comprised of broadly active “first The new emphasis placed on biodefense www.niaid.nih.gov/biodefense. responder” cells and other non-specific as a national priority has led the mechanisms that are the first line of National Institutes of Health (NIH) to defense against infection. NIAID-sup­ develop an expanded paradigm with ported research on methods to boost respect to biodefense product develop­ innate immune responses could lead to ment. NIH has always supported research fast-acting countermeasures to mitigate that generates new knowledge about dis­ the effects of a wide variety of bioterror ease and has worked to translate these pathogens or toxins. In addition, manip­ findings into vaccines, therapeutics, and ulation of the innate immune system diagnostics that protect public health. could pave the way toward powerful But to develop safe and effective products adjuvants that can be used to increase for biodefense as quickly as possible, NIH the potency and effectiveness of vaccines. needed to intensify and accelerate this Qualitative and quantitative assess­ process. Working in close collaboration ments of host response also are crucial with industry and academia, NIH is taking for creating vaccine candidates. For an active role in moving promising con­ example, Francisella tularensis, the bac­ cepts into advanced product development. terium that causes tularemia, is a highly The enhancements of NIH’s traditional infective, Gram-negative bacterium that process of research and development is a potential bioterrorist threat. As few have strengthened public health pre­ as 10 organisms may cause disease and paredness not just against Category A the bacterium can survive at low tem­ agents, but against emerging and re­ peratures for weeks. Studies of the emerging infectious diseases in general. immune response to a live attenuated The viruses, bacteria, and parasites that vaccine derived from the avirulent Live cause infectious diseases do not remain Vaccine Strain (LVS) suggest that it static, but continually and dramatically induces an incomplete immune response, change over time as new pathogens emerge activating some pathways but not others. and as familiar ones re-emerge with new In addition, the effectiveness of LVS properties or in unfamiliar settings. depends on a number of factors, including Emerging infections such as HIV, Ebola, the route of tularemia infection. While and SARS and re-emerging infections LVS protected mice against systemic such as influenza have shaped the course infection, it did not protect against of human history while causing incalcu­ aerosol infection. This suggests either that lable misery and death. Fortunately, the immune responses elicited by vaccination knowledge and products that will flow with LVS are not as well expressed in the from the NIH biodefense research pro­ lungs, or that immune responses raised by gram, including research results, intel­ LVS are less able to combat pulmonary lectual capital, laboratory resources, and

72 THE JORDAN REPORT 2007 ANIMAL MODELS FOR EMERGING INFECTIOUS DISEASES

Animal models are critical research tools in developing effective counter­ measures against emerging and re-emerging infectious diseases, including potential agents of bioterror. Scientists utilize animal models to evaluate novel therapeutics, diagnostics, drug treatments and vaccines, and to learn more about disease pathogenesis and host response. Such research has resulted in important public health advances, ranging from the devel­ opment of vaccines for diseases such as Hepatitis B, to drugs for chronic disorders such as diabetes.

The NIAID In Vitro and Animal Models Program has made many signifi­ cant contributions to the development of new therapies and continues to provide NIAID researchers with a range of resources to bring new thera­ pies and preventive measures from the laboratory to initial clinical testing in humans.

Examples of research advances made include those for anthrax and smallpox animal models. One of the challenges in anthrax models is that multiple interventions are often given. As each intervention is highly effective when used alone, it can be difficult to show the added value of multiple interventions. NIAID researchers have used rabbit animal models to demonstrate that antibiotics and vaccines can be additive, and have demonstrated in mice and guinea pig models that antibiotics and immunotherapeutics can be additive as well. Tests were conducted in post-exposure models, where animals have been exposed but are not yet showing clinical signs of disease. NIAID is currently exploring the rabbit and non-human primate as potential models for testing products.

CDC has the only laboratory in the United States permitted to conduct research using the smallpox virus. Therefore, smallpox animal model research is dependent on related, less lethal poxviruses, such as monkey­ pox. Less is known about these related viruses regarding the amount of virus needed to cause disease by various routes of transmission and the way in which the disease develops. Although scientists have collected promising proof-of-concept data for several drugs and vaccines against intravenously-acquired infection, it will be important to demonstrate effi­ cacy against respiratory-acquired disease as well. To this end, NIAID is exploring intranasal, intratracheal and aerosol infection models and assessing the impact of route of infection on disease progression.

SUPPORTING THE NATION’S BIODEFENSE 73 74 THE JORDAN REPORT 2007 Hepatitis C

pproximately 85 percent of indi­ infants born to HCV-infected mothers and very expensive. Their continued use viduals infected with hepatitis C demonstrated biochemical features of is expected to be very limited. A virus (HCV) become chronic car­ liver damage (alanine aminotransferase The current perception is that success­ riers of the virus. Chronic HCV infection (ALT) abnormalities) during the first 12 ful vaccines will need to induce both greatly increases the risk of developing months of life, although HCV-associated strong antibody responses and robust, liver cirrhosis and/or liver cancer. The liver disease is likely to be mild through­ long-lived, cytotoxic T-lymphocyte World Health Organization estimates that out infancy and childhood. Multivariate responses to overcome immune evasion there are 170 million chronic carriers of analyses of risk factors for cirrhosis by continual evolution of variant HCV HCV, equaling about 3 percent of the and/or liver cancer in HCV-infected species. Even though infection by HCV world’s population. In the United States, people demonstrated that increased age, generates antibodies, these antibodies an estimated 3.9 million people (1.8 male gender, and excessive alcohol con­ cannot resolve or neutralize the infection. percent of the population), are infected. sumption are all important factors. Vaccine studies in chimpanzees using The rate of infection is substantially Additional risk factors for liver cancer recombinant envelope glycoproteins higher in African Americans (8 to 10 are the presence of hepatitis B antibod­ showed limited protection upon challenge percent), who are also more refractory ies and HCV genotype 1 and 2. with virus, but both chimpanzee experi­ to current therapies. There are about Although HCV is the leading cause ments and epidemiological studies in 25,000 new infections annually, mostly of chronic viral hepatitis in the United humans suggest that vaccines may be among young adults who are intravenous States, a vaccine has been difficult to developed to prevent chronic infection. drug users (IDU); sexual transmission develop because of extensive genetic and DNA vaccines are now being tested in may also account for a proportion of possibly antigenic diversity among the chimpanzees, using envelope as well as cases. About 40 percent of liver transplants different strains. New variants known as core protein constructs. Virus-like parti­ are due to HCV-related liver failure and quasi-species arise quickly and frequently, cles (VLPs) made up of structural HCV 8,000 to 10,000 deaths per year result thus allowing escape from neutralizing proteins have been produced successfully from complications of chronic liver dis­ antibodies and cytotoxic T lymphocytes. in insect cells and may serve as a potential ease. Even though HCV infection rates Amino acid changes in many epitopes, vaccine model. Ribozymes, catalytic have fallen dramatically (declining from and particularly in the hypervariable RNA molecules that bind specifically to 180,000 over the past decade), the eco­ region 1 (HVR1) of the HCV envelope target RNA by an antisense mechanism, nomic toll exacted by HCV infection in glycoprotein E2, may play a role in are also being tested as a possible strategy the United States is enormous, estimated escape from neutralizing antibodies. for the treatment of HCV infection. at $1 billion per year. Recently, several new advances, A prophylactic vaccine candidate, Several investigators have reported a including the development of a fully based on the envelope glycoproteins E1 relatively high efficiency vertical transmis­ permissive cell culture system to produce and E2 of HCV, is currently being tested sion of HCV from mothers co-infected infectious HCV, have become available, by NIAID in the second of two Phase I with human immunodeficiency virus opening up more opportunities to study trials, using different adjuvants. Initial (HIV). Other major studies in the virus infection, to analyze the immune results from the first completed trial United States and Europe have failed to responses associated with virus clearance, indicate that the vaccine is safe and capable demonstrate transmission from HCV- and to test new anti-HCV drugs. However, of eliciting immune responses, which are positive mothers. Risk factors for trans­ the chimpanzee remains the only HCV still being characterized. A second vaccine, mission, which is assumed to occur in infection animal model available for for use primarily in chronically infected utero, include a high HCV RNA level in immunological studies to define the individuals as an immunotherapeutic the mother and the presence of specific correlates of immunity and protection. vaccine, is expected to enter clinical tri­ HCV variants. Results of a study of Chimpanzees are an endangered species als in 2007.

HEPATITIS C 75 The reconstructed images of a recombinant hepatitis C virus-like particle produced in cell culture. These images are three-dimensional representations of the HCV-like particle at high resolution. Visualizing the particles in this way enables researchers to understand how they interact at the molecular level with compounds important in fighting against HCV infection, and how to develop a vaccine to prevent HCV infection. Dr. Liang and his colleagues have shown that these HCV-like particles are promising as a vaccine candidate in animal models. They plan to conduct clinical studies in the near future. Courtesy of Dr. T. Jake Liang, Chief, Liver Diseases Branch, NIDDK Division of Intramural Research, NIH.

76 THE JORDAN REPORT 2007 HIV/AIDS

Overview

lthough there have been ambi­ tious human immunodeficiency A virus (HIV) prevention cam­ paigns over the years, HIV/AIDS contin­ ues to ravage many parts of the world, with approximately 40 million people living with HIV/AIDS globally. First reported in the United States in 1981, HIV/AIDS has become a worldwide pandemic. According to the United Nations, in 2005 there were an estimated 5 million new infections, more than 95 percent of which occurred in developing countries, and approximately 3.1 million deaths due to AIDS. Sub-Saharan Africa is the hardest hit, with more than 25.4 million people infected. South and Southeast Asia together account for more than 7.1 million infected people, with 1.4 million more in Eastern Europe and Central Asia, 2.1 million in Latin A school for orphans in Mlomba, Malawi houses 100 children, most of whom lost their parents to AIDS. Courtesy of Yoshi Shimizu / International Federation of Red Cross and Red Crescent Societies America and the Caribbean, 1.1 million in East Asia, 1 million in North America, 610,000 in Western and Central Europe, remains the best hope for ending the specific infection and to construct a and 35,000 in Oceania. Approximately AIDS pandemic. Although progress has vaccine that stimulates those responses. 14,000 people worldwide are newly been made, a safe and effective vaccine Since HIV can be transmitted through infected with HIV every day. In the has not yet been identified and much systemic and mucosal routes of expo­ United States alone, despite intensive needs to be done. The National Institute sure, by cell-associated and cell-free HIV prevention efforts and strong care of Allergy and Infectious Diseases (NIAID) virus, researchers are working to identify and treatment programs, the number of is committed to developing a preventive the components of the immune system annual new infections has not decreased HIV vaccine and, toward this end, sup­ that are essential to inducing immunity over the past 10 years. More than 40,000 ports basic biomedical research to better and preventing or controlling infection. new HIV infections are estimated to understand the relationship between HIV The two main types of immune occur in the United States every year and the immune system, preclinical responses are humoral immunity, which with 50 percent of those in persons development of new vaccines, and clinical uses antibodies to defend against free under the age of 25 and the majority in research and evaluation of novel vaccines virus, and cell-mediated immunity, racial and ethnic minorities, women, in all phases of clinical trials. which uses cytotoxic T lymphocytes and men who have sex with men. The most rational way to design an (CTLs) to directly kill or control infected Scientists and public health officials effective vaccine is to identify which cells. While earlier vaccine research agree that a preventive HIV vaccine immune responses protect against the focused primarily on vaccines that

HIV/AIDS 77 elicited antibodies, it is now generally believed that both arms of the immune response are needed to prevent or control HIV infection. As a result, vaccine concepts that induce a strong cellular response by eliciting CTLs are now being tested. More recently, vaccine concepts involving a “prime-boost” strategy—a combination of vaccines—has been tested. These vac­ cines stimulate a cellular immune response via CTLs (prime) as well as antibodies that bind to the virus (boost). Further­ more, in addition to systemic immunity, mucosal immunity, which includes anti­ bodies in mucosal secretions and cells in the lining of the reproductive tract and nearby lymph nodes, may also be required. Currently, NIAID is designing and testing new vaccine candidates based on research findings on the structural com­ ponents of HIV and on studies of immune response in small animals and Scanning electron micrograph of human immunodeficiency virus (HIV), grown in non-human primates. Vaccine candidates cultured lymphocytes. Virions are seen as small spheres on the surface of the cells. Courtesy of CDC / C. Goldsmith, P. Feorino, E. L. Palmer, W. R. McManus are also being constructed based on iso­ lates from many regions of the world, and several research groups are exploring fewer people would be passing the virus identification of new vaccine concepts. mixtures of viral components from differ­ to others. If this occurs in a high percent­ Basic research in the fields of HIV ent isolates and clades. NIAID is also age of people within a given population, pathogenesis, microbiology, immunology, testing new vaccine strategies using differ­ new infections could be reduced dramati­ virology, and animal model development ent adjuvants, immune modulators, and cally or even eliminated. The potential leads to discoveries about the biology of delivery components to optimize the drawback is that the benefits of a partially HIV such as the virus’ life cycle, virus-host immune response. effective vaccine could be offset by relax­ interactions, and mechanisms of disease When a vaccine is developed, the ation in the practice of safe behaviors, progression and transmission. These effectiveness of the vaccine will be critical. education, and other prevention efforts discoveries, coupled with knowledge While the goal is to find a vaccine that is because of perceived protection from gained through learning how the immune 100 percent effective in preventing infec­ infection. Thus, partially effective vaccines system responds to the virus, enhance tion, the initial HIV vaccines may not will have to be delivered in the context scientists’ ability to create and design protect all vaccinated people from infec­ of a broad prevention program. new vaccines to combat HIV infection. tion or may work to delay or prevent One example of an important scien­ disease rather than prevent infection. Vaccine Discovery tific advance is the elucidation of the Nonetheless, researchers recognize that With every new scientific advance, scien­ three-dimensional structure of the HIV even a partially effective vaccine could tists move one step closer to the discovery envelope and of broadly neutralizing have a significant impact on the worldwide and development of a safe, efficacious, antibodies, which has helped reveal spread of new infections. By decreasing cost-effective vaccine to prevent HIV specific targets for HIV vaccines and the number of people susceptible to HIV infection around the world. The road to highlight several defenses that the virus infection and/or able to infect others, a successful vaccine begins with the uses to evade attack. Research has also

78 THE JORDAN REPORT 2007 provided information on how the HIV in the understanding of the HIV/SIV in determining whether a vaccine candi­ envelope changes structure as HIV enters envelope structure and function, no HIV date should proceed into human clinical target cells, improved understanding of envelope vaccine has thus far succeeded trials. While these studies provide critical the specificity and role of antibodies and in eliciting broadly reactive antibodies information regarding safety and poten­ CTLs in HIV/simian immunodeficiency similar to those sometimes observed in tial efficacy, they also help scientists virus (SIV) infection, classified impor­ individuals who have been infected for a understand how the body responds to tant subsets of T cells that affect HIV long period of time. One theory is that a infection. Since HIV does not infect replication, and identified new potential few of the human broadly neutralizing monkeys naturally, researchers instead targets for HIV vaccines, such as the antibodies are actually derived from a carry out experiments with the closely HIV regulatory proteins rev and tat. pool of B cells that is usually deleted or related SIV. Combining parts of the There also have been important anergic in most individuals. Such rare, HIV envelope and the inner core of SIV, advances in vaccine technology, such as broadly neutralizing antibodies may researchers have engineered simian- improved systems for vaccine delivery have been isolated from individuals with human immunodeficiency viruses (e.g., codon-optimized DNA, novel viral immune dysfunctions that cause the (SHIVs), which mimic HIV infection and bacterial vectors, and cytokine adju­ body to make antibodies that attack an and can cause AIDS-like illness in macaque vants); vaccination method or strategy individual’s own tissues and cells. In one monkeys. These chimeric SHIVs allow (intramuscular, subcutaneous); and particular study, NIAID-supported researchers to study the immune responses laboratory techniques. These include researchers discovered human antibodies to the envelope-based HIV vaccines in a the development of the enzyme-linked that not only bind and neutralize HIV, live model, and the ability of these immunospot (ELISPOT) assay, which but also recognize cardiolipin, a lipid responses to stop or control the virus. allows researchers to detect and count molecule present on membranes of heart In addition to NIAID-supported cells producing cytokines in response to muscle, as well as other lipid moieties investigator-initiated research, NIAID specific HIV peptides; tetramer binding normally present on cell membranes. carries out AIDS vaccine-related studies in assays that detect T cells that recognize Another NIAID-supported investiga­ the non-human primate model through specific HIV peptides bound to major tor deciphered the crystal structure of the Simian Vaccine Evaluation Units histocompatibility complex (MHC) class SIV gp120 envelope glycoprotein. High (SVEUs). The SVEUs provide non-human I molecules; multi-color flow cytometry, resolution X-ray diffraction patterns of primates for immunization with candidate which enables enumeration of different crystallized protein can reveal the molec­ SIV or HIV vaccines selected by NIAID, subsets of T cells from a single specimen; ular interactions and structure of proteins. conduct initial assessment of the resulting and easier assays to measure neutralization Such studies have information that sig­ immune responses, challenge the animals of primary HIV isolates. All of these new nificantly enhances the understanding of with infectious virus, determine param­ discoveries serve to further the develop­ the structure of the HIV outer envelope eters of infection, and collect samples ment of HIV vaccines. and how neutralizing antibodies bind to for evaluation of immune responses and it. Ultimately, discoveries resulting from protection. There are currently about 20 Preclinical Development crystallographic studies will permit the active protocols involving more than 350 All promising vaccine candidates begin design and engineering of HIV envelope macaques. These studies help identify in the lab as a concept or design. However, vaccines that may elicit broadly neutral­ optimal vaccine vectors and are revealing there are many obstacles and scientific izing antibody responses. Preclinical whether vaginal viral loads can be detected challenges along the way. Overcoming studies of these constructs are essential in animals chronically infected with these challenges requires a better under­ for developing more promising vaccine SHIV and SIV. Some initial reports have standing of the interaction between HIV candidates. been encouraging. The eventual aim is to and the immune system. There are now more promising determine whether vaginal “shedding” of One critical area of investigation vaccine candidates in the preclinical virus is still detectable when blood viral seeks to address the difficulty of inducing pipeline than ever before. In light of loads become undetectable, either as a broadly reactive neutralizing antibodies this fact, HIV vaccine testing in animal result of vaccination or from “natural” against HIV. Despite significant advances models is becoming an important step control, as has been reported in some

HIV/AIDS 79 human studies among women on highly MAbs directed to non-linear V3 confor­ HIV/AIDS. The HVTN’s conduct of active antiretroviral therapy (HAART). mations (molecular shapes) are able to clinical trials is to include all phases, These studies are important compo­ neutralize more primary HIV isolates from evaluating experimental vaccines nents of NIAID’s preclinical vaccine compared to MAbs directed at other V3 for safety and ability to stimulate development process. regions. Experiments in macaques have immune responses, to testing vaccine A NIAID-funded scientist designed shown that low amounts of antibodies efficacy. Spanning four continents, the a study to test whether vaccines contain­ specific for the V3 region were able to network includes more than 25 clinical ing the HIV gene env bolster protection provide partial protection against viral sites in the United States, Africa, Asia, mediated by cellular responses to two challenge. South America, and the Caribbean; an other HIV genes, gag and pol. The study To circumvent the potential damp­ operations management center; a statis­ compared protection of macaques against ening of immune responses to candidate tical and data management center; and a a mucosal rectal challenge following adenovirus vector vaccines caused by central laboratory. immunization with DNA/modified vac­ preexisting immunity to common human Within the National Institutes of cinia Ankara (MVA) vaccines expressing adenoviruses, NIAID-supported investi­ Health (NIH), the NIAID Dale and either gag-pol-env or gag-pol. The study gators developed a recombinant chim­ Betty Bumpers Vaccine Research Center showed that all animals immunized with panzee adenovirus that is not neutralized (VRC) conducts research that facilitates vaccines expressing gag-pol-env rapidly by antibodies against that common the development of effective vaccines for controlled the challenge infection, whereas human adenovirus. Other NIAID sup­ human disease, with a primary focus on some of the animals immunized with ported approaches include the use of the development of vaccines for only gag-pol failed to control the challenge. “novel” human adenovirus serotypes as HIV/AIDS. The VRC’s activities include The gag-pol-env immunizations helped vectors to reduce neutralization by basic research to establish mechanisms in conserving CD4+ cell numbers. These human antibodies. of inducing long-lasting protective results demonstrate that while cellular immunity against HIV and other immune responses to gag and pol can Clinical Research pathogens that present special challenges control an immunodeficiency virus Vaccine development is a lengthy to vaccine development; the conception, challenge, immune responses to env process, as each stage of a clinical study design, and preparation of vaccine candi­ synergize with those of gag and pol in can take several years. Vaccine candidates dates for HIV and related viruses; labo­ achieving efficient and consistent con­ currently in Phase I, Phase II, and Phase ratory analysis and animal testing of trol of the challenge. These results also IIB clinical trials are at least a few years vaccine candidates; and clinical trials of suggest that in the presence of a strong away from being tested in large Phase III vaccine candidates. T-cell response, inclusion of env may help efficacy trials, which assess protective To ensure the effective integration protect against early programmed cell effects of the product and typically con­ and coordination of HIV vaccine research death of uninfected CD4+ T cells, a hall­ tinue for several years after enrollment efforts, in 2002 NIAID and the United mark of the acute phase of HIV infection. of the last patient. States Army Medical Research and In other recent preclinical studies, To accelerate the development and Materiel Command (USAMRMC) of researchers have identified the critical conduct of these clinical trials, NIAID the Department of Defense (DoD) parts of HIV gp120 responsible for currently supports a variety of collabo­ forged a collaboration through an inter­ inducing protective neutralizing anti­ rations, programs, and networks. The agency agreement. A team consisting bodies. Human monoclonal antibodies majority of the NIAID-supported HIV of U.S. Military HIV Research Program (MAbs) are capable of neutralizing a vaccine clinical trials are conducted (USMHRP) and NIAID staff was formed broad spectrum of HIV primary iso­ through the HIV Vaccine Trials Network to coordinate preclinical and clinical lates. Specific MAbs can bind to an (HVTN). Established in 1999 by NIAID, vaccine research and development efforts. important structure called the V3 loop the HVTN is a comprehensive global As part of this collaboration, a vaccine of the HIV-1 envelope gp120, which network of international scientists and preclinical testing laboratory utilizing helps the virus gain entry to and infect researchers whose mission is to develop standardized in vitro assays and animal target cells. Scientists have found that and test preventive vaccines against models has been established to test vac-

80 THE JORDAN REPORT 2007 cines supported by NIAID. This labora­ teins gp160 and gp120, as they represent envelope protein and its genetic diver­ tory will help identify assays and animal the primary targets for neutralizing anti­ sity, scientists learn more about its com­ models that predict human immuno­ bodies in HIV-infected individuals. The plex three-dimensional structure, genicity and thereby help NIAID priori­ first HIV vaccine clinical trial opened in conformation, and interaction with the tize vaccine candidates for further 1987 at the NIH Clinical Center. Tested HIV receptor. These advances may allow development. In addition, NIAID also in healthy, uninfected volunteers at low researchers to create vaccines that more supports the HIV Vaccine Design and risk of HIV infection, the gp160 subunit closely resemble the natural conforma­ Development Team (HVDDT) contract candidate vaccine caused no serious tion of the HIV envelope on the virion program which is exploring develop­ adverse effects. In 1992, NIAID launched surface. ment of more than 15 candidates. This the first Phase II HIV vaccine clinical Studies have demonstrated that pro­ program brings together the skills and trial, testing a recombinant subunit tection against HIV may also require expertise of private industry and academic gp120 vaccine in uninfected volunteers cell-mediated immune responses that research centers that have identified with a history of high-risk behavior such eliminate HIV-infected cells. The cell- promising vaccine concepts and have as injection drug use, multiple sex part­ mediated immune response involves the plans for targeted testing in humans. All ners, or sexually transmitted infections. activation of specific CD8+ CTLs that of the original four contactors— More recently, the HVTN conducted a target HIV-infected cells. To elicit CD8+ Wyeth-Lederle, Advanced BioSciences Phase I trial using a nef-tat fusion pro­ CTL responses, scientists employ viral or Laboratories, Chiron Corporation, and a tein (HVTN 041), followed by varying bacterial vectors to mimic infection by consortium headed by the University of doses of gp120. Although these early can­ safely delivering specific HIV genes and New South Wales in Australia—have made didates, as well as many others that tar­ inducing production of HIV proteins experimental AIDS vaccines that have get HIV envelope proteins, stimulated within cells. Because scientists design entered human clinical trials. Two more production of antibodies, antibody levels vectors to carry only a small part of the HVDDT contracts were made in fiscal decreased within a relatively short period total HIV genetic material, these vectors year 2005 to the Children’s Research of time. The formulations and dosages cannot cause HIV infection. There are Institute and Chiron Corporation, mak­ used in the vaccine clinical trials induced different types of viral vector vaccines ing a total of 11 awards since the pro­ low levels of neutralizing antibodies and currently being used, including poxviruses gram’s inception. rarely elicited cytotoxic T cells, which such as canarypox, fowlpox, and MVA, kill HIV-infected cells. which is a weakened vaccinia virus; Vaccine Strategies A major challenge in HIV vaccine alphavirus; and adenovirus type 5 Currently, there are a number of vaccine development arises from the vast genetic (Ad5), which is related to the virus that strategies under investigation, including diversity of the virus and its structural causes some forms of the common cold. component or subunit vaccines (a struc­ proteins. As the virus replicates within The canarypox vaccine was the first can­ tural piece of HIV such as an envelope infected individuals, and after transmis­ didate HIV vaccine shown to induce a or a core protein); live vector vaccines (a sion to others, it continues to mutate CTL response against diverse HIV live bacterium or virus modified to genetically, evolving into different sub­ genetic subtypes. As a result, NIAID carry genes that encode HIV proteins); types around the world. Thus, for a vac­ conducted a subsequent study in peptide (small pieces of HIV proteins) cine to be effective on a global scale, it Uganda using a recombinant canarypox or fusion protein vaccines (two proteins will need to induce immune responses based on clade B. This study demon­ merged together); DNA vaccines (direct that are broadly reactive to the many strated that a vaccine could induce injection of HIV DNA sequences) and different subtypes of HIV. The initial cross-clade cellular reactivity against vaccine combinations such as the prime- envelope vaccines induced antibodies various subtypes of HIV. In addition, by boost strategy. that were largely specific for clade B successfully completing this trial, Early in the AIDS epidemic, most of isolates, the subtype of HIV that is pre­ researchers showed that a vaccine trial the initial HIV vaccine research focused dominantly found only in the United could be conducted in Africa with high on component or subunit vaccines States and Europe. As research unlocks scientific and ethical standards, thus directed against the HIV envelope pro­ additional information about the HIV

HIV/AIDS 81 paving the way for additional interna­ and high risk of HIV infection. Studies multigene, multiclade HIV vaccines to tional HIV vaccine trials in Africa. have shown that this approach can stimu­ reach clinical Phase II, marking an Since then, there has been an late cellular immunity, resulting in CTLs important milestone in the search for a expanding number of Phase I and II that can kill infected cells, as well as the single vaccine strategy that targets U.S. vaccine trials, with increasing participa­ production of HIV-neutralizing antibod­ subtypes of HIV as well as clades caus­ tion in the developing world, using ies, which can stop HIV from infecting ing the global pandemic. The partners in strategies that elicit cell-mediated cells. Thus, the combination approach the coordinated trials include the HVTN, immune responses. In 2005, NIAID’s continues to hold promise because it the USMHRP, and the International HVTN, in collaboration with Merck, stimulates production of HIV-neutralizing AIDS Vaccine Initiative (IAVI). The initiated a Phase IIB “test-of-concept” antibodies and cellular immunity. HVTN is conducting a trial in the trial (HVTN 502) of a recombinant ade­ At present, the HVTN has eight clinical United States, Caribbean, South America novirus vaccine at sites in the United trials under way to further evaluate the and South Africa; the USMHRP is con­ States, the Caribbean, and South combination vaccine approach. In addi­ ducting a trial in Kenya, Tanzania, and America. Designed by Merck, the inves­ tion, in 2003, NIAID began working Uganda; and IAVI is conducting a trial tigational vaccine contains three replica­ with the DoD and the Royal Thai in Kenya and Rwanda. tion-defective adenoviruses, each Government to initiate a Phase III efficacy expressing one of three HIV genes: gag, trial (RV144) using a prime-boost com­ Challenges and Future pol, and nef. bination comprised of Aventis Pasteur’s Directions Researchers also have been exploring recombinant canarypox vector vaccine The scientific challenges that must be other possible vaccines, including DNA candidate (ALVAC-HIV vCP1521) and solved to develop an effective preventive vaccines (containing one or more HIV VaxGen’s recombinant gp120 (AIDSVAX HIV vaccine have proven more daunting genes). Injection of a DNA vaccine, usu­ B/E) designed for Southeast Asia. The than those faced by researchers develop­ ally intramuscularly, causes cells to take goal of this trial is to determine if these ing vaccines against other diseases. For up the DNA and produce HIV proteins vaccines can either prevent infection or virtually all infections, including most by normal cellular mechanisms, stimu­ control HIV, if infection occurs. By viral infections, if the patient does not lating cell-mediated immune responses. November 2005, this trial fully enrolled die the immune system ultimately clears Early studies demonstrated that the first more than 16,000 uninfected volunteers. the infection and the person becomes DNA candidates were safe but did not In 2002, VRC initiated the first mul­ immune to subsequent exposure to the induce strong immune responses. ticlade vaccine clinical study, a Phase I infectious agent, sometimes for life. This is However, new technologies are being trial using a multiclade, multigene DNA not the case for HIV. The biggest obsta­ developed for DNA vaccines, such as plasmid vector, which was later combined cle is that immune-mediated eradication codon-optimized and particle-formu­ with an adenoviral vector (ADV) boost. of HIV from the body, with subsequent lated DNA vaccine candidates, that are The VRC subsequently conducted other naturally induced immunity, simply expected to enhance their performance. Phase I vaccine trials using the prime- does not occur. Even after more than 60 In 1992 researchers turned their boost strategy in 2005. These vaccines were million cumulative HIV infections since attention to a prime-boost approach to shown to be well-tolerated and elicited the beginning of the pandemic, there has improve the immunogenicity of HIV cellular and humoral responses. The not been a single documented case in vaccines. In this strategy, the first vaccine vaccines incorporate HIV genetic mate­ which a person with established HIV primes the initial immune response, fol­ rial from clades A, B and C, which cause infection has completely eliminated the lowed by another vaccine to boost the about 90 percent of all HIV infections virus from the body. This fact alone response. Prime-boost approaches have around the world. Recently, the VRC makes it difficult for scientists to develop utilized combinations of DNA vaccines, candidates have progressed into Phase II a vaccine that can induce a protective viral vector vaccines, and subunit or testing of VRC’s multiclade HIV-1 six- immune response. This means a vaccine peptide vaccines. The combination vac­ plasmid DNA vaccine in combination that only mimics natural infection will cine approach has been shown to be safe with a recombinant ADV boost in HIV-l likely not be sufficient. and immunogenic in volunteers at low uninfected adults. These are the first

82 THE JORDAN REPORT 2007 an HIV vaccine to be effective on a global scale. Researchers also need to be prepared for the various possible clinical trial out­ comes, so as to assess the value from an individual and a public health perspective. Outcomes may range from preventing the establishment of infection (sterilizing immunity), to preventing or delaying disease of a volunteer who becomes infected after vaccination (controlled infection). Even if a vaccine were not able to prevent infection, it is hoped that it may keep the level of virus in the blood low enough in the vaccine recipient so that the recipient remains healthy and DNA vaccination using the needle-free Biojector device. Credit: NIAID is not able to infect others. The greatest public health value of a vaccine will be Scientific Challenges infection becomes established, the virus in its ability to prevent transmission. Years of research have helped provide a continually undergoes genetic changes, Animal studies can help answer critical solid understanding of how HIV evades and many variants may arise within an questions that cannot be answered either and ultimately defeats the immune infected person. Thus, researchers will in humans, because of undue risk, or by response. First, because the primary need to determine the significance of using computer modeling or laboratory target of its devastation is the immune strain variation within individuals and tests. Although non-human primates are system itself, HIV disables the very cells among populations when developing not the ideal animal model, they repre­ that are responsible for fighting it. Second, HIV vaccines. Given these scientific sent the best available surrogate model HIV is a retrovirus, which means that it challenges, the need to better understand for research on AIDS pathogenesis and can integrate its viral sequence into the the intricacies and complexities of the vaccine development. chromosomes of infected cells. Thus, the immune response against HIV has never virus can shield itself from immune been greater. Expanding Global Vaccine Research attack for many years, only to emerge Researchers are seeking to improve In response to the changing HIV pandemic when the infected cell is activated by the upon current vaccine designs so that the and the relatively low incidence of HIV immune system to fight another infection. vaccines will induce broadly reactive, infection in industrialized countries, Third, HIV conceals the protein compo­ long-lasting neutralizing antibodies and even among higher risk groups, HIV nents that can induce a protective CTL responses. Although scientists have vaccine testing must in large part be carried immune response, and therefore presents found clues about the correlates of out in countries where the rate of new itself to the body in a way that makes it immunity for HIV, efficacy trials will be infections is highest and where different difficult for the immune system to respond required to confirm immune correlates. subtypes of HIV are being transmitted. effectively. Fourth, HIV is genetically It is hoped that once a vaccine is shown NIAID established the HVTN to build diverse and rapidly changing, especially to induce at least partial protection in global capacity and infrastructure with a in its outer coat proteins; its mutability humans, researchers will be able to deci­ special focus on pursuing an interna­ allows HIV to evade the modest protective pher the type, magnitude, breadth, and/or tional vaccine research agenda. To responses the immune system is naturally location of the immune responses asso­ expand upon and better coordinate able to make. Initially, a person is ciated with that protection. Additionally, global vaccine research activities, in infected with only one or a limited the issue of clade or subtype diversity addition to increasing collaboration, number of HIV variants. Once HIV around the world must be addressed for efficiency, and flexibility, NIAID is

HIV/AIDS 83 restructuring all of its HIV clinical trials NIAID has invested in building a working around the world, until recently there was research networks. The new structure is partnership with community representa­ minimal international coordination and designed to encourage greater integra­ tives around the world. Among these support for HIV vaccine development tion of vaccine, prevention, and treat­ efforts, community advisory boards are efforts. Following a proposal by a group ment research and address high-priority essential components at all NIAID- of scientists, the Global HIV Vaccine research questions, particularly in sponsored vaccine trial sites and within Enterprise was created to foster collabo­ resource-limited settings where AIDS is the research network. Community advisory ration, cooperation, and transparency in most devastating. boards provide advice and perspective the conduct of HIV vaccine clinical trials on whether trials are ethical and reason­ on a global scale. In June 2004, the Recruitment and Community Support able based on the concerns and needs of “Group of Eight” (G8) countries and Another major challenge is to recruit the community. In 2001, NIAID launched President George W. Bush endorsed the enough volunteers willing to participate the National HIV Vaccine Communica­ Enterprise at the 30th G8 Summit at Sea in clinical trials. More vaccines will be tions Campaign to stimulate and Island, Georgia. The Enterprise is a con­ studied in the next two years than in the enhance the national dialogue concern­ sortium of international scientists and past five years combined. The 97 Phase ing HIV preventive vaccines and to organizations committed to accelerating I, II, and III HIV preventive vaccine create a supportive environment for the development of preventive vaccines clinical trials currently under way or future vaccine studies. The campaign’s for HIV/AIDS. The overarching purpose planned will require thousands of vol­ activities include partnerships with is to efficiently bring resources to bear unteers, both in the United States and national and local community groups, on gaps in HIV vaccine research, while internationally. Within the United the development and provision of allowing flexibility in how research is States, one of the biggest challenges is the resources and materials, and promotion carried out. A strategic plan was pub­ low participation of women, minorities, of HIV Vaccine Awareness Day on May lished online in January 2005 in the and high-risk populations in clinical tri­ 18th of every year. journal Public Library of Science Medicine. als. These groups are the most in need of Importantly, the plan emphasizes that an HIV vaccine because they are dispro­ Collaborations and Partnerships the major difficulties encountered in the portionately affected by HIV/AIDS, and The Partnership for AIDS Vaccine development of an HIV vaccine are their participation is needed to ensure Evaluation (PAVE) was created in 2003 scientific. The plan proposes five major that a potential vaccine is safe and effective as a voluntary consortium of U.S. gov­ activities to address the scientific priorities: in all groups of people. In developing ernment agencies and key U.S. govern­ (1) creation of HIV vaccine development countries, researchers are taking care to ment-funded organizations involved in centers or consortia to address the key maintain equal partnerships with local the development and evaluation of scientific obstacles; (2) creation of a net­ researchers and help ensure infrastruc­ HIV/AIDS preventive vaccines and the work of individuals and companies with ture (clinical laboratories, supplies, and conduct of HIV vaccine clinical trials. It vaccine manufacturing expertise to facil­ equipment) and increase training. Some is a collaborative effort to achieve better itate advancement of improved candidates; populations that are at higher risk of harmony and increased operational and (3) development of a global system of HIV infection (such as high-risk women cost efficiencies in HIV vaccine develop­ laboratories that will standardize labora­ and injection drug users) are often ment and in the conduct of HIV vaccine tory evaluation parameters; (4) sharing of harder to recruit and retain in a clinical clinical trials, especially Phase III trials, common reagents; and (5) development trial. In some populations, there may be through serving as a forum and clearing­ of a network of clinical research training a general mistrust and misunderstanding house for information sharing and plan­ centers, all with the full engagement of of vaccine research that creates barriers ning. PAVE is currently assessing scientists from developing countries. to HIV vaccine trial recruitment, which international trial site capacity and stan­ In response to recommendations by researchers are working to address. dardizing laboratory procedures among the Global HIV Vaccine Enterprise, in To help raise awareness and create partner organizations. 2005, NIAID created a Center for and sustain a supportive environment Although substantial resources have HIV/AIDS Vaccine Immunology (CHAVI), suitable for clinical HIV vaccine research, been devoted to HIV vaccine research a virtual center that links a large group

84 THE JORDAN REPORT 2007 of domestic and international scientists working to elucidate the correlates of DALE AND BETTY BUMPERS VACCINE RESEARCH CENTER immune protection against HIV, and to use that knowledge to design a vaccine that elicits protective immune responses. The primary focus of activities at the Dale and Betty Bumpers Vaccine CHAVI’s mission includes addressing Research Center (VRC) remains the development of an effective other key immunological roadblocks to HIV/AIDS vaccine. However, over the last several years, the VRC HIV vaccine development and designing, research program has also expanded its activities to include vaccine developing, and testing novel HIV vac­ development for Ebola, severe acute respiratory syndrome (SARS), West cine candidates, as defined by NIH and Nile virus, and influenza. Since being established in 1999, the VRC as identified by the strategic plan of the has made 22 clinical grade vaccine products, including 8 HIV vaccine Global HIV Vaccine Enterprise. products. Twenty-four clinical trials have been completed or are ongo­ ing, and 7 more are planned in the next year. More than 70 percent of Conclusion HIV research funds at the VRC are allocated to translational product Although many difficult challenges lie development, as compared to basic research. In the process of address­ ahead, both scientific and technological, ing the need for an HIV/AIDS vaccine, novel technologies—such as scientists are moving closer to finding DNA vaccines, viral vectors, and recombinant proteins—have been an HIV vaccine. They continue to expand developed. When appropriate, these technologies have been applied to their knowledge of the science, overcome other emerging diseases as noted above. obstacles in development, and advance candidate HIV vaccines through clinical Activities at the VRC stem initially from basic science discovery pro­ trials, all in collaboration with scientists grams in immunology and virology. The strategy has been to identify and organizations from around the the most relevant vaccine candidates, move these candidates quickly world. The combined efforts of NIAID’s into production, and then into clinical trials. This effort requires robust HVTN, the Dale and Betty Bumpers and reliable production and immune assay technologies. Major VRC, industrialized partners on HIV advances in the past year include completion of the Vaccine Production Vaccine Design and Development Plant and initiation of its first cGMP manufacturing effort, Ebola cell Teams, collaborators in the U.S. military, banking, as well as completion of the National Vaccine, Immune, T- and other partnerships are moving HIV Cell, and Antibody Laboratory. vaccine research forward and providing hope and optimism for realizing the goal of identifying a safe and effective HIV vaccine. than $600 million. These funds have impact studies at the earliest stages of enabled NIAID to establish a compre­ concept genesis and evaluation Sources hensive and vibrant set of programs that HIV vaccine research has long been an support all stages of the vaccine devel­ HIV Research and Design Program— integral part of NIAID’s research portfo­ opment pipeline, including Grants to support concept testing in lio, with the goal of identifying a safe animal models, development of poten­ and efficacious vaccine to prevent HIV Dale and Betty Bumpers Vaccine Research tial vaccine candidates, studies of infection and/or disease. Over the past Center (VRC)—Intramural vaccine immune correlates, and animal model 10 years, the HIV/AIDS program has research with a primary focus on the development received an influx of funds that has development of HIV vaccines enabled it to grow exponentially. From Integrated Preclinical/Clinical AIDS 1996 to 2005, funding for HIV vaccine Phased Innovation Grant Program— Vaccine Development Program—Grants research at the NIH increased from Investigator-initiated HIV vaccine that target research at the preclinical/ slightly more than $100 million to more research involving high-risk/high­ clinical interface HIV Vaccine Design and

HIV/AIDS 85 Development Teams—Consortia of sci­ entists from industry and/or academia who have identified promising vaccine concepts and work under milestone- driven contracts

Vaccine Development Resources— Contracts for the manufacture and testing of vaccine candidates

Simian Vaccine Evaluation Units— Testing of promising SIV and HIV candidates in non-human primates

HVTN—Global research network with the capacity to conduct all phases of clinical trials, from evaluating candidate vaccines for safety and the ability to stimulate immune responses, to testing vaccine efficacy

86 THE JORDAN REPORT 2007 Human Papillomavirus (HPV)

uman papillomavirus (HPV) is potentially protective the name given to a group of antibody responses H viruses that includes more than against other strains 100 different strains. Almost every cervi­ of HPV. cal cancer in the United States and In anticipation of abroad is caused by sexually transmitted FDA approval of HPV infection with HPV. Two dominant vaccines, the Gates strains of HPV, types 16 and 18, together Foundation announced cause 70 percent of new cases of cervical in June 2005 that it cancer. In 2006, a vaccine to prevent would grant $12.9 infection by these two HPV types was million to the World approved by the U.S. Food and Drug Health Organization, Administration (FDA). This vaccine, the International based primarily on technology developed Agency for Research Low-Risk and High-Risk HPVs. This chart shows the three groups of by scientists from the National Cancer genital HPV strains. While the majority of infections with high-risk HPVs on Cancer, Harvard Institute’s (NCI) Center for Cancer clear up on their own, a few can trigger cervical cancer over time. University, and the Courtesy of NCI Research, offers great hope for reducing Program for Appropriate the global burden of cervical cancer. Technology in Health to Using molecular biology techniques, ing results. The VLP vaccines were more establish systems to ensure quality con­ NCI scientists engineered a vaccine to than 90 percent effective at preventing trol in vaccine distribution, monitor the prevent HPV infection. They demonstrated infection with the virus that can lead to impact of different HPV vaccination that the major HPV capsid protein by the development of premalignant cervical strategies, and facilitate introduction of itself can self-assemble into non-infectious abnormalities. Studies to date have the vaccines worldwide. virus-like particles (VLPs) that are highly demonstrated that the vaccine prevents immunogenic. Immunization with these infection for up to four years after vacci­ VLPs, which lack any infectious or nation. Studies are under way to determine oncogenic genetic material, stimulates if a booster, in addition to the three initial production of large quantities of anti­ intramuscular injections, will be necessary bodies that prevent HPV virus infec­ for long-term protection. Merck submit­ tions in humans. ted an application for FDA approval and NCI licensed the technology to two on June 8, 2006, Gardasil was approved pharmaceutical companies, Merck and as the first vaccine developed to prevent GlaxoSmithKline (GSK), to develop HPV cervical cancer, precancerous genital vaccines commercially. Both companies lesions, and genital warts due to HPV are running large-scale Phase III trials of types 6, 11, 16, and 18. their versions of an HPV vaccine. GSK’s NCI’s involvement in optimizing

targets the two most oncogenic HPV HPV vaccine development continues. Illustration of the virus-like particles in the HPV vaccine. Like the real human papillomavirus, these strains, 16 and 18. Merck’s vaccine also NCI scientists have developed the first vaccine participles have the same outer L1 protein targets strains 16 and 18, as well as high-throughput assay to enable HPV coat, but they have no genetic material inside. This structure enables the vaccine to induce a strong strains 6 and 11, which cause about 90 vaccine developers to monitor protective protective immune response. Courtesy of NCI percent of genital warts. Phase II trials antibody responses long term, and test by both companies produced encourag­ whether their new vaccines can induce

HUMAN PAPILLOMAVIRUS 87 CANCER VACCINE DEVELOPMENT AT NCI

The National Cancer Institute’s (NCI’s) Center for Cancer Research (CCR) is home to one of the strongest immunology and virology com­ munities in the world. CCR scientists perform basic, translational, and clinical research as a collaborative unit in the Center of Excellence for Immunology (CEI). Their goal is to further the discovery, development, and delivery of novel immunologic approaches to the prevention, diag­ nosis, and treatment of cancer and cancer-associated viral diseases.

Therapeutic Cancer Vaccines CEI researchers have made significant contributions to the ever-expanding field of therapeutic cancer vaccines. They have identified numerous novel cancer antigens, devised novel approaches to vaccine design, improved vaccine delivery, and discovered ways to optimize vaccine- induced immune responses with cytokines and co-stimulatory molecules. CEI clinicians recently initiated a pilot study that was the first clinical trial to combine radiation with a cancer vaccine for treating prostate cancer. By showing that such combination therapy is safe and well-tolerated, CCR is leading the way toward finding alternative treatments for patients with localized disease who receive radiation or surgery and then relapse. In several clinical trials, there is evidence that immune responses to vaccines are associated with prolonged survival. Several vaccines and combination protocols are being developed at NCI and are being evaluated at more than 60 cancer centers around the country for testing in clinical trials. At least two of these vaccines are progressing successfully from Phase II to Phase III studies.

One promising immunotherapy under development at NCI is inter­ leukin-15 (IL-15), which is being investigated for inclusion in cancer vaccines. IL-15 seems to improve the body’s natural response to infec­ tion and disease. In addition, IL-15 helps generate cytotoxic T lympho­ cytes and natural killer cells; inhibits activation-induced T-cell death and the generation of suppressor T cells that can suppress immune response against a tumor; and facilitates the survival of memory T cells that identify antigens previously encountered by the immune system.

88 THE JORDAN REPORT 2007 Influenza

Introduction reassorted influenza A virus acquires the Current State of Science ability to spread efficiently from person At present, licensed trivalent vaccines of nfluenza virus infection remains to person, a pandemic may result. This two types of influenza vaccine are avail­ among the leading causes of pre­ is thought to be the mechanism by which able to prevent seasonal influenza: the I ventable morbidity and mortality. H2 and H3 avian influenza virus sub­ inactivated vaccine (TIV) and the live Annual epidemics and infrequent types were introduced into human attenuated influenza vaccine (LAIV). pandemics occur in all age groups influenza viruses to spark global TIV and LAIV are similar in that they worldwide. In the United States, pneu­ influenza pandemics that began in 1957 incorporate three strains of influenza monia and influenza together are and 1968, respectively. and are updated each year to reflect the among the top 10 causes of mortality circulating strains identified during and influenza viruses are estimated to be Vaccine History global surveillance and recommended associated with 36,000 deaths annually. Influenza vaccines are the primary means for use in vaccine preparation. Despite prior vaccination or infection, of preventing influenza disease and MedImmune, Inc., received the first the population’s susceptibility to influenza related complications in all age groups. license in the United States for LAIV in infection continues because point muta­ Influenza viruses were first isolated in 2003 for its product, FluMist, derived tions accumulate in the two major surface the early 1930s. The earliest influenza from cold-adapted live attenuated donor glycoproteins of the virus, hemagglutinin vaccines were whole virus vaccines that strains of influenza A and B. More than (HA) and neuraminidase (NA). Over were produced by growing the virus in 25 years of research and development time, often within a single year, accumu­ embryonated chicken eggs and inacti­ were required to bring this product to lation of mutations (“antigenic drift”) vating it with formalin. Clinical trials licensure. Much of this research was results in sufficiently different antigenic sponsored by the U.S. military were conducted in National Institute of characteristics of the HA and NA proteins, conducted in healthy adults in the 1940s Allergy and Infectious Diseases (NIAID) making previous influenza vaccines less and demonstrated that the vaccine was labs and in clinical trials supported by effective. Vaccines therefore must be highly effective in preventing influenza NIAID and the private sector. The reformulated annually to combat the illness and its complications, provided unique characteristic of these cold- coming year’s prevalent strains. there was a good match between the adapted influenza viruses is their ability While antigenic drift is the basis for viruses in the vaccine and those causing to grow at 25°C and inability to grow at the yearly review and frequent update the epidemic. As a result of those clinical temperatures greater than 38°C (tem­ of seasonal influenza vaccines, the form studies, licenses were issued in 1945 to perature sensitivity). This characteristic of antigenic variation that results in several companies in the United States allows the virus to undergo limited pandemics (“antigenic shift”) occurs for production of the first influenza replication in the cooler nasopharynx, when a completely new subtype of type vaccines for commercial use. While con­ but not the warmer lower respiratory A influenza is introduced into the temporary inactivated influenza vaccines tract. FluMist is approved to prevent human population and begins to trans­ are still produced in embryonated eggs, influenza illness in healthy children and mit efficiently. Because of the segmented a series of improvements in manufacturing adolescents, ages 5 to 17 years, and nature of the influenza virus genome, over the years has resulted in purified healthy adults, ages 18 to 49 years. In co-infection of animals or humans with vaccines that maintain their immuno­ July 2006, MedImmune began the two influenza viruses can result in the genicity but are less reactogenic. process of obtaining approval for a exchange of genetic material between Additional progress and advances in refrigerator-stable formulation of the viruses. The resulting viruses, which vaccine technology are continuing. FluMist, and for expansion of the age have exchanged genetic material, may indications to include children 6 to 59 have acquired a new HA or NA. If a months of age.

INFLUENZA 89 A CDC researcher in a BSL-3 laboratory conducts an experiment to investigate the pathogenicity and transmissibility of emerging H5N1 viruses. Courtesy of CDC / Greg Knobloch

There are continuing studies to look (producer of the TIV called Fluzone and the United States and lessen the impact at the immune response to live attenuated now merged to become sanofi pasteur); of future delays or shortages of influenza virus vaccines in persons less than 5 Chiron Corporation (producer of the vaccines, NIAID rapidly initiated a years of age and greater than 50 years. TIV Fluvirin and now merged with Phase III trial to evaluate safety and Additional investigations are needed to Novartis), and MedImmune, Inc., pro­ immunogenicity of GlaxoSmithKline’s determine whether it is safe to use LAIV ducer of the LAIV marketed as FluMist. (GSK) TIV, called Fluarix, for use in in persons with asthma, reactive airway In October 2004, Chiron Corporation in healthy adults. This multi-center clinical diseases, or other chronic disorders of Liverpool, United Kingdom, was notified trial was conducted by the NIAID-sup­ the pulmonary or cardiovascular systems by the Medicines and Healthcare products ported Vaccine and Treatment or other current contraindications, includ­ Regulatory Agency (MHRA) that the Evaluation Units (VTEUs) [2]. The trial ing children or adolescents receiving company’s license was being suspended began in December 2004 and provided aspirin or other salicylates, persons with for three months. As a result, Chiron the clinical information needed by GSK a history of Guillain-Barré Syndrome, notified the U.S. Food and Drug to support approval by the U.S. FDA in pregnant women, and persons with a Administration (FDA) that none of its August 2005 of the Biologics License history of hypersensitivity to any com­ Fluvirin influenza vaccine would be Application for Fluarix. Fluarix became ponent of the vaccine or to eggs. available for distribution in the United the first vaccine approved through the In 2003 there were three manufactur­ States during the 2004-2005 influenza FDA’s new accelerated approval process. ers licensed to provide influenza vaccine season [1]. In March 2006, the FDA issued two in the United States: Aventis Pasteur To bring additional manufacturers to draft guidance documents to further

90 THE JORDAN REPORT 2007 delineate how accelerated approval enrolled approximately 200 people over These are comprised of individual viral might be implemented for interpan­ the age of 65 and administered one of proteins produced in cells and purified to demic and pandemic influenza vaccines. three different doses of the influenza a level not possible with vaccines started vaccine: the standard dose (15 mcg), two from a whole virus. These purified pro­ Expanding Population times the standard dose (30 mcg), and tein vaccines include vaccines using only Protection four times the standard dose (60 mcg). the HA protein, or the HA protein in Populations at special risk for complica­ Study results showed that participants in combination with NA or internal proteins. tions of influenza virus infection have the highest-dose group (60 mcg) had 44 Additionally, a variety of DNA vaccines been expanding, both because of the aging to 79 percent higher levels of antibody are being developed. In these vaccines, of the population and because additional than did those who received the standard viral DNA sequences are included in a risk factors for significant morbidity dose of vaccine. The higher doses also plasmid or viral vector, which, once and mortality related to influenza have increased the number of elderly volunteers injected into a person, enter the cells of been recognized. Recommendations for achieving levels of antibody that have the host where they cause production of the use of inactivated influenza vaccines been associated with protection against limited amounts of the viral proteins in the United States include individuals influenza. Increasing the antigen content that in turn elicit an immune response. 50 years of age or older and individuals of inactivated vaccines may provide a The ideal vaccine, one providing 6 months of age and older with chronic straightforward approach to improving protection against any strain of influenza underlying diseases that place them at protection in the elderly. and not needing to be updated or admin­ increased risk for complications from istered every year to protect against newly influenza infection. In 2006, the Advisory New Vaccine Strategies emerging strains, is a goal not yet realized. Committee for Immunization Practices Influenza vaccines have been prepared However, research to develop such a (ACIP) extended the recommended age in eggs for many years, but new vaccine universal vaccine is currently being sup­ for influenza vaccination to include all technologies are facilitating the develop­ ported by NIAID and others. One strategy children age 6 months to 5 years, because ment of innovative types of vaccine being pursued is a “common epitope” of their high risk for increased clinic production platforms. For example, the vaccine, which utilizes highly conserved and emergency room visits for compli­ Department of Health and Human influenza proteins as targets. Although cations from influenza. The expanded Services (HHS), including NIAID, has the HA and NA surface glycoproteins of recommendation is a step toward encouraged and supported multiple influenza change frequently, many of the increasing rates of influenza vaccination manufacturing efforts to develop cell- internal proteins are less variable. In for the population as a whole [3]. based influenza vaccines. particular, the M2 protein is being Over the last 10 years, annual Cell- and egg-based production of explored as an option. The M2 protein influenza vaccination rates in persons 65 influenza vaccines has been aided by acts as an ion channel between the out­ years of age or older have steadily risen; advances made in reverse genetics tech­ side and inside of the virus membrane. however, the effectiveness of the current niques, which allow a vaccine strain to A small portion of the M2 protein, its vaccine in preventing influenza illness in be designed rather than selected. Some ectodomain or M2e, is exposed on the some elderly populations can be as low influenza viruses do not grow well in surface of the influenza virus. While it is as 30 to 40 percent. The NIAID Influenza eggs and therefore cannot be used in the still in early stages of investigation, M2e Research Program supports research to production of a vaccine. Reverse genet­ may act as an additional immune stimulus improve the effectiveness of influenza ics improves the chances that a new to augment the immune response and vaccines in naïve populations and those virus can be generated that does grow increase protection. at high risk, especially the elderly. well in eggs or tissue culture. Innovative vaccine strategies also NIAID-supported VTEUs conducted a Innovative vaccine strategies are provide new options to develop vaccines study to assess the immunogenicity and being developed that do not require rapidly in response to a newly emerging reactogenicity of a current U.S. vaccine replication of the whole influenza virus, strain. If successful, these strategies could formulation given at increasing doses in including purified protein vaccines pro­ further increase vaccine production the elderly population [4]. The study duced by recombinant DNA technology. capacity and enhance preparedness

INFLUENZA 91 against seasonal influenza and potential transmit between humans, but the avian influenza A viruses to acquire the ability pandemic strains of influenza [5]. features may result in a virus that is new to transmit efficiently from one person to humans and is therefore pathogenic. to another, precipitating a pandemic. Pandemic Influenza The human population has little or no Limited human transmission associ­ As the understanding of influenza immunity to a novel influenza subtype ated with poultry outbreaks of other viruses has increased, it has become that emerges in this way, and these avian influenza subtypes has also been clear that wild aquatic birds, such as strains can cause very severe flu epi­ observed. H9N2 virus infections occurred ducks and shore birds, are the most demics or pandemics. This is thought to in two children in China in 1999 and important reservoir of influenza A have occurred in 1957-58 (Asian Flu) one child in Hong Kong in 2003, all of viruses. Strains containing all 16 HA and 1968-69 (Hong Kong Flu). However, whom recovered. In 2003, 89 cases of and all 9 NA subtypes have been iso­ sequence and phylogenetic analyses of H7N7 were reported in the Netherlands, lated from these birds. The majority of the complete genome of the 1918 with most victims reporting only mild wild birds infected with influenza A influenza virus suggest that the 1918 symptoms, including conjunctivitis, viruses have no symptoms, although pandemic strain was an avian strain that although 1 death occurred in an infected rarely strains emerge that can cause adapted to a human host and did not person. Serological evidence was found severe disease or death. Those strains reassort in a secondary host [6]. for a human H7N2 infection in Virginia that cause severe disease and death in In 1997, the H5N1 strain of avian in 2002 and a patient with an underlying the domestic chicken are termed highly influenza infected humans in Hong Kong medical condition was hospitalized for pathogenic avian influenza (HPAI) directly from infected poultry. During influenza that was later determined to viruses. HPAI viruses share a characteris­ this outbreak, 18 people were confirmed be an H7N2 subtype. In 2004, Canadian tic motif in the HA that permits efficient as having H5N1 infection, and 6 of these poultry workers contracted H7N3, virus replication in organs not normally people died. The outbreak was successfully resulting in mild illness in each patient. affected by influenza viruses including controlled by culling approximately 1.5 Historically, emergence of a pandemic the brain, heart, liver, and kidneys. The million chickens during a 3-day period. influenza strain is both infrequent and subtypes most likely to be or develop In 2003, H5N1 reappeared with two unpredictable; however, because of the into HPAI include H5 and H7 viruses. cases (one fatal) in family members from number of human infections that have Influenza A viruses can readily jump Hong Kong who had recently traveled to occurred, the public health community is genus and species barriers. Wild birds China; a third member of the family died concerned that H5N1 may emerge as may infect domestic poultry such as ducks in mainland China from an unconfirmed the next pandemic strain. Recent NIAID and chickens. From there, the next step respiratory illness. As of early 2007, H5N1 vaccine development efforts have in the infection chain can be other farm influenza cases in humans have been focused on vaccines against H5N1 animals such as pigs and horses. An inter­ confirmed in Azerbaijan, Cambodia, influenza strains that have infected people mediate host is not needed for humans China, Djibouti, Egypt, Indonesia, Iraq, in Asia. World Health Organization to be infected, as has been amply Thailand, Turkey, and Vietnam. Worldwide, as reference laboratories have produced demonstrated by H5N1 influenza A of early 2007, 270 human cases had been several reference virus strains for use in viruses in Asia and Europe and H7N7 confirmed, with more than 160 deaths. manufacturing vaccines against H5N1, viruses in the Netherlands since 2003. Extensive H5N1 outbreaks in poul­ using representative H5N1 strains Typically, direct infection of humans try have occurred in Asia and Europe, including A/HongKong/213/2003, with an avian influenza virus requires raising concerns that transmission to A/Vietnam/1194/2004, A/Vietnam/1203/ intense, close contact with sick or dead humans may become more widespread. 2004, A/Indonesia/5/2005, A/whooper birds or feces from sick birds. Clustering of H5N1 cases suggests that swan/ Mongolia/244/2005, A/barheaded Human and avian influenza viruses limited human-to-human transmission goose/Qinghai Lake/1A/2005, and can reassort to form a chimeric virus has occurred among persons with A/turkey/Turkey/1/2005. with features from both human and intense, close contact. However, it is not In 2004, NIAID awarded contracts avian viruses. The human features of the clear whether genetic changes other to support the production and clinical virus may allow it to readily infect and than reassortment could permit H5N1 testing of H5N1 vaccines to sanofi pasteur

92 THE JORDAN REPORT 2007 doses of vaccine were well tolerated. The antibody response to the vaccine corre­ lated with dosage, with the highest response occurring in subjects receiving the 90 mcg dose. To evaluate the ability to boost individuals previously immunized with an H5N1 vaccine, subjects in the above study who consented to be in a follow-on study received a third identical dose of the H5N1 vaccine. Immuno­ genicity results are expected shortly. Intradermal administration of 3 mcg or 9 mcg of the H5N1 vaccine produced by sanofi pasteur was also evaluated in healthy adults and found to be less immunogenic than two 45 mcg doses given via intramuscular injection. Research to evaluate higher intradermal doses of the H5N1 vaccine is underway. Testing the sanofi pasteur H5N1 vaccine in the elderly and children began in early 2006 and preliminary results suggest that the vaccine is well tolerated and immunogenic, similar to the results in An illustration of the flu virus depicting the layer of HA and NA protein spikes projecting from its surface, as well as the eight segments of single-strand RNA inside the virus. Credit: NIAID adults. In addition, evaluation of adju­ vanted H5N1 vaccines, including those formulated with aluminum hydroxide (sanofi pasteur and Novartis) or MF59 and Chiron Corporation. The reference H5N1 vaccine and is conducting a series (Novartis) is currently under way virus for production of these vaccines of safety and dose-ranging immunogenic­ through the NIAID VTEUs. was generated at St. Jude Children’s ity studies through its VTEU network. A 96-patient study explored the Research Hospital using reverse genetics In a multi-center, double-blind two-stage safety and immunogenicity of 4 different to provide the HA and NA genes from Phase I/II study, the vaccine produced doses of an investigational vaccine for A/Vietnam/1203/2004 (isolated from a under NIAID contract by sanofi pasteur H9N2 influenza with and without Vietnamese patient who died from was evaluated in 451 healthy adults aged Chiron’s adjuvant MF59 [8]. The vaccine H5N1 infection) and the remaining 18 to 64 years. Two intramuscular doses was well tolerated and all vaccine formu­ genes from A/PR/8/34, a non-virulent of the subunit, inactivated H5N1 lations containing the adjuvant MF59 strain. The HA protein from A/Vietnam/ influenza vaccine were administered at proved highly immunogenic. The lowest 1203/2004 was modified by replacing 90 mcg, 45 mcg, 15 mcg, or 7.5 mcg of dose contained 3.75 mcg of antigen per the HA cleavage sequence, which has HA per dose, or placebo [7], and subjects dose, a quarter of the dose used in seasonal been shown to be directly linked to were followed for safety analysis influenza vaccines. In marked contrast, virulence in H5 viruses, with a sequence throughout their participation. Sera the unadjuvanted vaccine induced signif­ from an avirulent strain, making the were obtained before each vaccination icantly lower antibody titers and did not virus safe for use in vaccine production. and 28 days after the second vaccination, reach levels achieved by the adjuvanted NIAID has recently supported the and tested for H5 antibody by neutraliza­ vaccine following any of the antigen production of several lots of inactivated tion and hemagglutination-inhibition. All doses tested, which ranged from 3.75 to

INFLUENZA 93 are not yet available. In December 2006, the first human trial of DNA vaccine to prevent H5N1 avian influenza began at the National Institutes of Health Clinical Center in Bethesda, MD. The vaccine was designed by scientists at NIAID’s Dale and Betty Bumpers Vaccine Research Center, and targets newer strains of the H5N1 virus currently circulating in Indonesia. The trial will enroll 45 volunteers between the ages of 18 and 60. Fifteen will receive placebo injections and 30 will receive three injections of the investigational vac­ cine over two months and will be followed for one year.

References 1. Centers for Disease Control and Prevention, Updated interim influenza vaccination recom­ mendations—2004-05 influenza season, MMWR Morb Mortal Wkly Rep 2004;53: 1183-1184. 2. Treanor J et al., Rapid licensure of a new, inac­ tivated influenza vaccine in the United States, Hum Vacc 2005;1(6):239-244. A transmission electron micrograph (TEM) of two avian influenza A (H5N1) virions. 3. Smith NM et al., Prevention and control of Courtesy of CDC/ Cynthia Goldsmith/ Jackie Katz influenza: Recommendations of the Advisory Committee on Immunization Practices [ACIP], MMWR Morb Mortal Wkly Rep 30 mcg. is testing the vaccines in an isolation 2006;55(No.RR-10):1-42. In 2005, NIAID announced a cooper­ unit at Johns Hopkins Bloomberg 4. Keitel W et al., Safety of high doses of ative research and development agreement School of Public Health Center for influenza vaccine and effect on antibody responses in elderly persons, Arch Intern Med with MedImmune to produce and test at Immunization Research in Baltimore, 2006;166:1121-1127. least one LAIV for each of the 16 variations Maryland, to assess vaccine safety, infec­ 5. Gerhard W et al., Prospects for universal influenza virus vaccine, Emerg Infect Dis of HA, beginning with vaccines for the tivity, and immunogenicity. Results of 2006;12:569-574. highest priority HA subtypes, including preclinical testing of the team’s H5N1 6. Taubenberger JK et al., Characterization of the H5. These vaccines will be based on the vaccine candidates were reported in 1918 influenza virus polymerase genes, Nature 2005;437(7060):889-893. same cold-adapted virus currently used September, 2006 [9]. The candidate vac­ 7. Treanor J et al., Safety and immunogenicity of for the licensed live attenuated FluMist cines were prepared using H5N1 viruses an inactivated subvirion influenza A (H5N1) vaccine, N Engl J Med 2006;354(13):1343­ vaccine. However, like the inactivated isolated from human cases in Hong 1351. vaccine used to manufacture vaccines Kong in 1997 and 2003, and Vietnam in 8. Atmar RL et al., Safety and immunogenicity for clinical trials, the HA gene will be 2004. The resulting vaccines protected of non-adjuvanted and MF59-adjuvanted influenza A/H9N2 vaccine preparations, Clin modified as necessary to alter virulence mice and ferrets from infection with Infect Dis 2006;43:1135-1142. determinants. homologous and antigenically distinct 9. Suguitan AL et al., Live, attenuated influenza A H5N1 candidate vaccines provide broad Both NIAID and MedImmune will heterologous wild-type H5N1 viruses cross-protection in mice and ferrets, PLoS conduct laboratory studies to assess the that were isolated in Asia between 1997 Med 2006;3:e360. safety of the vaccines before they are and 2005. Results from a clinical trial used for clinical trials. MedImmune is using an H5N1 LAIV and from an ear­ manufacturing the vaccines, and NIAID lier clinical trial of a similar H9N2 LAIV

94 THE JORDAN REPORT 2007 Malaria

hile significant advances have and insecticide-resistant mosquito vectors, implementation of this plan, NIAID has been made in malaria research, the development of a malaria vaccine sought to define an accessible development W the disease remains a major has been given high priority throughout pathway for promising malaria vaccines. health problem in the world’s tropical the research community. As a result of the increasing attention areas. More than 40 percent of the world’s In 1997, the National Institute of that malaria has received in recent years, population lives in areas at risk for Allergy and Infectious Diseases (NIAID) coupled with the improved infrastructure malaria transmission. According to the launched its Research Plan to Accelerate to produce and evaluate candidate malaria World Health Organization (WHO), Development of Malaria Vaccines. Four vaccines, an increasing number of malaria approximately 300 million to 500 million elements were identified as being critical: vaccines have been tested in clinical tri­ cases of malaria occur worldwide each (1) improved access to well-characterized als. As of December 2006, 25 vaccine year, resulting in more than 1 million research materials; (2) discovery and candidates were being tested in clinical deaths, primarily among young children preclinical testing of new vaccine candi­ trials (see Table 1). Based on the results in Africa. Given the disease’s devastating dates; (3) production and evaluation of of the clinical trials, further clinical eval­ toll on public health, and the fact that candidate malaria vaccines; and (4) clin­ uation is planned for 20 candidates. disease control has been further inhibited ical research and trial preparation sites by the spread of drug-resistant parasites in endemic areas. Through the systematic

Table 1: Candidate Malaria Vaccines in Clinical Development

(Source: Adapted from Initiative for Vaccine Research, World Health Organization: www.who.int/vaccine_research/documents/RainbowTable_ClinicalTrials_December2006.pdf; accessed February 22, 2007)

Targeted Stage Recent Clinical Trials of Candidate Vaccines Phase I Phase II

Pre-erythrocytic Stages 3 6

Asexual Erythrocytic Stages 11 2

Sexual Stages 1 0

Multistage Combination 0 2

Total 15 10

MALARIA 95 Vaccines Against Pre-Erythrocytic 30 percent protection against clinical confirm these preliminary findings, they Stages of Malaria Parasites malaria; in contrast to prior studies, suggest specific strategies and priorities During the 1990s, many studies were however, the duration of protection for future development. Recent studies carried out with various candidate malaria appeared to last at least 18 months. also suggest that an alternative adjuvant vaccine formulations that included Furthermore, somewhat unexpectedly, may elicit greater protection against different adjuvants. These studies either the vaccine in this study also appeared clinical malaria, but further studies with failed to demonstrate adequate to confer 58 percent protection against larger numbers of participants will be immunogenicity or failed to demonstrate severe malaria. Based on these findings, required to verify this. An initial study adequate protection against challenge plans are now under way to carry out to assess the combination of RTS,S and infection. In early 1997, however, inves­ additional clinical studies of this vaccine another recombinant protein correspon­ tigators working at the Walter Reed in infants and in different epidemiologic ding to the pre-erythrocytic antigen Army Institute of Research (WRAIR) settings. GlaxoSmithKline Biologicals, thrombospondin-related adhesion reported that a candidate vaccine (RTS,S), the corporate sponsor for these studies, protein/sporozoite surface protein 2 based on recombinant fusion proteins anticipates licensure as early as 2011 and (TRAP/SSP2) resulted in an apparent of the malaria CS protein and the hepa­ has recently committed funds for the loss of protective efficacy compared to titis B surface antigen, could provide construction of a manufacturing facility. RTS,S alone. These results suggest that protection against challenge infection with a homologous parasite when the vaccine was formulated with an appro­ priate novel adjuvant. These results were encouraging and validated the importance of incorporating into vaccine formulations strong adjuvants that elicit appropriate immune responses. Subsequent studies, however, indicated that the protection conferred against experimental challenge by this vaccine alone was not long lived. An additional study carried out in The Gambia demonstrated that under condi­ tions of natural exposure to malaria, the candidate vaccine could elicit protection, defined as a delay in time to first infec­ tion, in semi-immune adult men. Such protective immunity did not appear to be restricted to homologous parasites, In Niger, a quarter of all children do not reach their fifth birthday. Half the deaths among children under but again was short lived. Overall vaccine five are from malaria. Courtesy of John Haskew / International Federation of efficacy was 34 percent, but was higher Red Cross and Red Crescent Societies (71 percent) in the first 9 weeks of follow- up than in the last 6 weeks. Volunteers Studies are already under way to interactions among constituent antigens who received a fourth dose the next improve the formulation and investigate in vaccines may actually be detrimental year, prior to the onset of the malaria other means by which the immunity rather than beneficial, and thus serve as season, again exhibited statistically sig­ provided might be enhanced. Recently, a cautionary note for combination of nificant protection (47 percent) over a vaccine- or antigen-specific production RTS,S with other antigens. 9-week follow-up period. In subsequent of interferon (IFN) has been identified Building on the increased awareness studies carried out in children in as an important correlate of protection. of the importance of strong adjuvants, Mozambique, the vaccine also elicited Although further studies are needed to some investigators have returned to the

96 THE JORDAN REPORT 2007 concept of immunizing with long syn­ approach to overcome the genetic and further work will be needed to thetic peptides (LSPs) formulated with restriction, investigators created a con­ improve the characteristics of this can­ stronger adjuvants. Investigators at the struct that also incorporated a “univer­ didate. University of Lausanne in Switzerland sal” T-cell epitope (i.e., one that was not An alternative approach is to couple carried out a Phase I clinical trial of an subject to narrow genetic restriction) synthetic peptides to virus-like particles. approximately 100-amino-acid synthetic and was subsequently shown to elicit One advantage of this approach is that peptide corresponding to the C-terminal robust immune responses in mice and in the peptides can sometimes be constructed portion of the CS protein, formulated humans with diverse genetic back­ so as to mimic the structure that occurs with a strong adjuvant (Montanide ISA grounds. In contrast to the preceding in the native parasite protein (these are 720). Subsequent analyses showed that MAP vaccine, this vaccine was not asso­ often called “mimotopes”). Both the CS the vaccine was safe and well tolerated ciated with significant hypersensitivity repeat B-cell epitope and the apical and elicited antibody and cellular reactions in trial participants. merozoite antigen 1 (AMA1) immune responses, including antigen- Other investigators have made LSPs ectodomain have been constructed as specific production of IFN. based on the sequence of various malaria mimotopes and coupled to viral-like An alternative approach that antigens, including the CS antigens of particles based on influenza. In a Phase I appears promising is to identify specific Plasmodium falciparum and Plasmodium trial these constructs were reported to regions of the CS protein that stimulate vivax, a number of which have completed be well tolerated and immunogenic. In immune responses and then incorporate Phase I trials. In general, these studies addition, the antibodies elicited inhibited several copies of those regions into a have demonstrated that LSP-based vac­ parasite invasion of liver cells in an in synthetic structure called a multiple cines are safe and immunogenic. A vitro assay. antigenic peptide (MAP). MAPs based Phase II experimental challenge study Attention also has been directed to on CS protein structures have been has also been completed for a P. falciparum the non-repeat domains of the CS shown to elicit high antibody titers in construct, but the results have not yet polypeptide. A genetically conserved animal models and are capable of boosting been reported. region within these domains has been preexisting malaria-specific immune Two critical issues for synthetic implicated in parasite attachment to responses. One potential problem associ­ peptide vaccines have been the difficulty liver cells. Although shown to be safe ated with evaluation of synthetic peptide- of manufacturing such candidates repro­ and immunogenic in a clinical trial, a based vaccines such as MAPs is that ducibly, and the likelihood that linear vaccine based on a genetically engineered human genetic variations may limit peptides may not adopt the conformation CS-derived polypeptide from which the immune responses to the vaccine. This of the native parasite protein. Alternative central repeat region was excised failed is particularly important because the strategies, therefore, have been pursued to confer protection against experimental candidate vaccine might be rejected as to develop new platforms for delivery challenge in the immunized volunteers. non-immunogenic if the responsive indi­ of epitopes. Recently the B- and T-cell While malaria vaccine efforts in the viduals are not adequately represented in epitopes studied in the MAP trials have past have focused primarily on the the initial immunogenicity study. Two been incorporated into a recombinant humoral aspects of immunity, increasing approaches have been studied to deter­ virus-like particle based on a molecu­ attention is being directed to the impor­ mine how genetic factors impact immune larly engineered version of the hepatitis tant role played by T cells. In addition to responses to CS-based MAP vaccines, B core antigen (HBc). This particle enhancing antibody responses and con­ including a recent innovative Phase I appeared to function as a particularly ferring immunological memory, T cells clinical trial designed to ensure that an immunogenic platform, and the engi­ also mediate cytotoxic immunity and adequate number of pre-identified respon­ neered CS-HBc particle elicited robust induce the production of cytokines, such der individuals was included. Though immune responses to P. falciparum as IFN. CS-responsive T-cell clones have these individuals mounted significant sporozoite antigens in animal studies. In been established from cells of vaccinees immune responses, hypersensitivity Phase I clinical trials, however, the immunized with attenuated parasites, reactions were seen in a significant immunogenicity of the construct in and may prove to be useful in future number of trial participants. In another humans was shown to be much lower, studies on the development of immune

MALARIA 97 responsiveness. Epitopes of CS polypep­ it was recognized by cells from all the rodent CS protein. Since then various tides recognized by helper T cells, as volunteers, and further analysis indicated investigators have initiated studies of well as by cytotoxic T cells, have been that it is highly expressed in sporozoites. different prime-boost combinations for identified and are being incorporated Pre-erythrocytic antigens also have a number of different antigens. into recombinant vaccine candidates for been incorporated into multicomponent Although none of the regimens studied further testing. vaccines. In the case of DNA vaccines, a to date have demonstrated clinically rel­ To identify new candidate vaccine construct incorporating the gene for the evant protection, results have been components, investigators have used a CS antigen was evaluated as a “proof of encouraging, and these regimens are still variety of techniques. For example, concept” in a clinical study carried out under active investigation. Under a reverse immunogenetics allowed investi­ by the U.S. Navy Malaria Program and recent contract, NIAID-supported gators to identify a peptide component its collaborators. The construct elicited investigators produced a novel candidate of a liver-stage parasite protein (LSA-1) cell-mediated immune responses in malaria vaccine based on a replication- from individuals who are resistant to study volunteers, but did not elicit anti­ deficient adenovirus serotype 35 vector severe malaria that is efficiently recog­ body responses and did not confer pro­ encoding the CS antigen; clinical trials nized by cytotoxic T cells. This result, in tection against experimental challenge. of this candidate began in December, combination with epidemiologic data, The possibility has also been raised that 2006. This construct is especially inter­ supported the case for evaluating an incorporating additional pre-erythrocytic esting because it was previously shown LSA-1 based vaccine and new recombi­ antigens or epitopes into a DNA vaccine that a single dose of an adenovirus nant viral vectors expressing LSA-1. might improve efficacy. In a subsequent encoding the CS gene could confer pro­ Recombinant proteins based on LSA-1 Phase I/IIa clinical trial, DNA plasmids tection against rodent malaria, and also sequences have now been made and are for five different antigens (CSP, could serve as an effective prime in a beginning to enter preclinical and clini­ TRAP/SSP2, Exp1, LSA-1, LSA-3) plus a prime-boost regimen with RTS,S in a cal development. Other liver-stage anti­ plasmid for human GM-CSF were eval­ study of immune responses in rhesus gens (e.g., LSA-3) are also being uated. The five different antigens all macaques. evaluated in preclinical and clinical elicited T-cell responses and did not Although these advances are prom­ studies for their potential as candidate appear to interfere immunologically ising, some investigators have returned to malaria vaccines. with each other; however, they failed to the concept of an attenuated sporozoite The availability of the genomes for elicit an antibody response, and none of vaccine for malaria. In the past, con­ P. falciparum as well as Plasmodium the vaccinees were protected against cerns have been raised about the safety, yoelli has also allowed investigators to experimental challenge. reproducibility, production scaleability, identify novel antigens that might be Investigators are expressing pre- and distribution of such a vaccine. developed as potential vaccines. One erythrocytic stage antigens in a variety Considerable progress has been made, approach has been to identify genes that of viral and bacterial vectors and evalu­ however, toward the various steps neces­ are essential to parasite development ating their potential either as vaccines sary for commercial development and and might be susceptible to genetic or by themselves or as part of a heterolo­ distribution of an irradiated sporozoite immunologic manipulation. In an alter­ gous prime-boost strategy in which one vaccine. A related approach, which nate approach using a combination of type of vaccine is used to prime and a builds on the recent availability of the proteomic and genomic data, second is used to boost the immune Plasmodium genomes, has been to iden­ researchers were able to identify 27 response. Heterologous prime-boost was tify genes that are critical for parasite potential sporozoite antigens. Sixteen of first demonstrated as a strategy in development (e.g., in the liver stage), these antigens were recognized by blood malaria vaccination more than 10 years and then to use molecular genetic tech­ cells from individuals immunized with ago when NIAID-supported investiga­ niques to knock out expression of those irradiated sporozoites, suggesting they tors showed that immunizing mice genes. Using this approach, NIAID- could be targets of protective immunity. against rodent malaria could be done supported investigators demonstrated Indeed, one antigen, PFL0800C, most effectively when using different the feasibility of a genetically attenuated appeared particularly promising in that viral vectors encoding the gene for the sporozoite vaccine in a murine model.

98 THE JORDAN REPORT 2007 species do not carry out substantial N­ or O-linked glycosylation, site-specific mutations were introduced into the native sequence to prevent glycosylation in the transgenic animals. When glyco­ sylated and non-glycosylated versions of these recombinant proteins were com­ pared in a head-to-head study in Aotus monkeys, only the non-glycosylated ver­ sion elicited protective immunity. Together with studies of the same recombinant protein expressed from a baculovirus construct in insect cells, these results suggest that the extent of glycosylation in some expression sys­ tems may alter or obscure the immuno­

The Anopheles gambiae mosquito, a malaria vector. Courtesy of CDC / Jim Gathany genicity of protective epitopes. A recombinant version of the ectodomain of AMA1 in which the glycosylation That result was independently con­ 42-kD fragment for assessment of safety sites were also mutagenized has been firmed for a different gene by other and immunogenicity in malaria- shown to elicit protective immunity in investigators. Efforts are now under way endemic populations has been carried Aotus monkey studies as well. to translate these findings into a compa­ out in adults in Kenya and in Mali, and A number of groups have carried rable vaccine for P. falciparum. plans are under way for pediatric trials. out clinical trials of AMA1-based vac­ Investigators at the NIAID Malaria cines. In addition to some of the struc­ Vaccines Against Asexual Vaccine Development Branch (MVDB) tural issues involved in expressing Blood Stages of Malaria have also made recombinant proteins AMA1, this antigen is also quite poly­ Parasites based on two allelic variants of the P. morphic. NIAID investigators have In collaboration with GlaxoSmithKline falciparum MSP1 42-kD protein. The studied expression in a number of dif­ and the U.S. Agency for International recombinant proteins were expressed in ferent systems to try to determine the Development, investigators at WRAIR E. coli and then allowed to refold to obtain optimal process for maintaining both recently expressed the 42-kD C-terminal their native conformations. In Aotus conformation and yield. To address the fragment of the major MSP1 in monkeys, these proteins were shown to issue of polymorphism, investigators are Escherichia coli. Based on reactivity with be immunogenic, and protection against also assessing combinations of different a panel of monoclonal antibodies, the experimental challenge with infected red variants of the antigens for the ability to antigen appears to be conformationally blood cells was associated with antibody elicit immune responses to multiple correct. The antigen was subsequently titers to the immunogen. Phase I clinical variants. In a recent Phase I trial of formulated with the same adjuvant used trials are currently under way. AMA1-C1 (a combination of two in the RTS,S studies. In clinical trials Under a cooperative research and recombinant proteins based on the most carried out in the United States, this development agreement, NIAID and divergent variants) formulated with vaccine appeared to be safe and Genzyme Transgenics Corporation eval­ Alhydrogel, antibody responses were immunogenic, although the addition of uated the feasibility of producing genet­ detected in 92 percent of volunteers the MSP1 42-kD antigen to RTS,S did ically engineered animals capable of after three immunizations, with equal not appear to enhance protective effi­ secreting a recombinant version of the reactivity to both of the AMA1 compo­ cacy against experimental challenge. A MSP1 42-kD C-terminal fragment in nents. Purified IgG obtained from these clinical trial of the recombinant MSP1 the animals’ milk. Because Plasmodium individuals also inhibited parasite

MALARIA 99 a Phase I clinical trial is under hydroxide, were studied. Although both way. Clinical trial material for the formulations were immunogenic, the DBA vaccine is also expected to Montanide formulation was found to be be available in the near future. unacceptably reactogenic. The vaccines SE36, a recombinant protein induced cytophilic antibody responses, based on serine repeat antigen, and in vitro and in vivo assays for anti- has also undergone a Phase I trial. body-dependent cell-mediated inhibi­ The structures of various tion (ADCI) of parasite growth recombinant protein-based candi­ suggested a sustained immune response date vaccines, e.g., MSP1 19, AMA1, eight months after the final vaccine dose. EBA-175 RII, and DBA, have also The glycophosphotidylinositol recently been determined, and are (GPI) anchor of several malaria proteins yielding new insights about critical has been identified as a putative malaria targets of protective immunity. For toxin responsible for several of the clini­ example, the recently published cal manifestations of severe disease. As a crystal structure of EBA-175 RII result, it has been proposed that suggested that particular amino immune responses directed against the acids were involved in dimerization GPI anchor might underlie an “anti-dis­ of the molecule and in binding to ease” vaccine intended to limit the clini­ sugar residues on the red-cell sur­ cal pathology associated with malaria face molecule glycophorin A. Site- infection. A major obstacle to testing directed mutagenesis of these this hypothesis has been the inability to Public health campaigns, such as the distribution of residues provided further support­ obtain the requisite amounts of GPI. insecticide-treated mosquito nets by the International Federation of Red Cross and Red Crescent Societies, ing evidence for the roles of these Recent advances in automated carbohy­ are attempting to protect millions of children throughout developing countries. Courtesy of John Haskew / International residues. Since EBA-175 is a mem­ drate synthesis, however, have made it Federation of Red Cross and Red Crescent Societies ber of a family of parasite mole­ possible to make large quantities of GPI cules that have been implicated in reproducibly. Preclinical data obtained growth in vitro. Subsequently, it was red cell invasion and are structurally with such material supports the concept shown in preclinical studies that the related, the results of the crystal struc­ that anti-GPI responses elicited by a addition of CpG oligodeoxynucleotide ture are likely to be informative for a vaccine can limit severe disease, but to this vaccine enhanced functional number of molecules. Indeed, the struc­ have also demonstrated that in the antibody responses. As a result, a Phase I ture of DBA has recently been deter­ absence of clinical signs and symptoms, study using AMA1-C1 adjuvanted with mined, and was found to be similar to high levels of parasites can appear in the both Alhydrogel and CpG was con­ that of EBA-175. The availability of such blood. Additional preclinical studies are ducted. The addition of CpG to the structural features and their association now under way to evaluate the safety and alum-based vaccine greatly enhanced with functional aspects may prove use­ efficacy of these novel vaccine candidates. the antibody response to AMA1-C1. ful for targeted vaccine design in the Chimeric vaccines comprising dif­ Other antigens that are being pro­ future. ferent antigens are now beginning to duced in recombinant protein expres­ In addition to the studies with vac­ undergo evaluation. Such combinations sion systems include region II (RII, the cines based on recombinant proteins, include GLURP-MSP3, PF CP-2.9 (a red cell binding site) of the 175-kD ery­ two clinical trials have been carried out combination of AMA1 and MSP1 19-kD), throcyte binding antigen (EBA-175) of recently with vaccines based on LSP ver­ and MSP1 and EBA-175. P. falciparum, and its paralog in P. vivax, sions of MSP3 and the glutamine-rich the Duffy binding antigen (DBA). protein (GLURP). In a Phase I trial of Material suitable for use in clinical trials MSP3, two different adjuvant systems, has been produced for EBA-175 RII, and Montanide ISA 720 and aluminum

100 THE JORDAN REPORT 2007 Vaccines Against Sexual Multicomponent Vaccines ologic settings. Additional improvements Stages of Malaria Parasites Multicomponent vaccines directed in the apparent efficacy of the vaccine and Mosquito Vector against different antigens and different may also be possible and are actively Components (Transmission- stages of the parasite life cycle may offer being investigated. Just as important, Blocking Vaccines) an advantage over single-component however, are significant scientific and Transmission-blocking vaccines are vaccines because they may provide mul­ technical advances that have led to the designed to eliminate malaria from tiple levels of protection. Such vaccines creation of a robust portfolio of candi­ regions of the world with low transmis­ also may reduce the spread of vaccine- date malaria vaccines supported by a sion intensity. Antigens from the sexual resistant strains, which can arise when number of research agencies and public- stages of the malaria parasite that can the parasite changes a surface protein to private partnerships, and the necessary induce transmission-blocking activity avoid detection by the immune system. elements of a defined clinical development have been identified. Investigators at the Almost 10 years ago, a blood-stage pathway are being put in place. NIAID MVDB have expressed a recom­ vaccine (SPf66) developed in Colombia Under its research plan for malaria binant protein in yeast corresponding to was reported to delay or suppress the vaccine development and its Global a 25-kD molecule found in P. falciparum onset of disease. In a randomized, dou­ Health Research Plan for HIV/AIDS, (Pfs25). Immunization with this mole­ ble-blind trial conducted in Colombia, Malaria, and Tuberculosis, NIAID has cule elicits transmission-blocking anti­ the vaccine was reported to have an stimulated research in this area with bodies in animals; from these studies, overall efficacy of 40 percent. Two other recent initiatives and support activities. however, it is clear that attaining and clinical trials in South America reported Novel vaccine targets, delivery systems, maintaining a high titer of transmis­ similar results. These studies, however, and alternative strategies to prime and sion-blocking antibody is likely to be were carried out in areas of low or sea­ boost protective immune responses dif­ important for efficacy. Phase I clinical sonal malaria transmission, and thus the ferentially are being investigated. The testing of this vaccine candidate formu­ utility of this vaccine in areas of high Malaria Research and Reference Reagent lated with alum has been conducted, transmission and in other geographic Resource Center (MR4), a resource for and preliminary results indicate that locations was questioned. To address the collection of malaria research and improved formulation will be required. these issues, randomized, double-blind, reference reagents, has been established Experiments are under way to improve controlled clinical trials were carried out at the American Type Culture Collection the preclinical profile and immuno­ in Tanzania, The Gambia, and Thailand. to provide a central source of quality- genicity. A recombinant antigen corre­ In the Tanzanian study, the estimated controlled, malaria-related reagents and sponding to a similar 25-kD antigen efficacy of SPf66 was 30 percent, but information to the international malaria found in P. vivax has also been pro­ with wide variability. In the Gambian research community. NIAID also contin­ duced by recombinant DNA technology and Thai studies, however, no significant ues to collaborate with a number of by MVDB and shown to elicit transmis­ efficacy was demonstrated. A later study partners in supporting large-scale sion-blocking activity in monkeys. In a in Brazil also did not demonstrate any sequencing of genomes of Plasmodium recent Phase I clinical trial, Pvs25H efficacy of SPf66. parasites. Such efforts are expected to adsorbed to Alhydrogel elicited no seri­ result in the identification of new targets ous adverse events and was shown to be Future Directions for potential vaccines and drugs. Finally, immunogenic. In a membrane feed In recent years, the landscape for efforts are also in progress to expand assay intended to evaluate transmission- malaria vaccines has changed in capabilities to produce candidate blocking activity, functional antibody remarkable ways. Certainly considerable malaria vaccines and to accelerate their responses were observed. Unfortunately, progress has been made on various fronts. evaluation domestically and interna­ the vaccine formulated with alum is Promising results have been obtained tionally. In recent years, NIAID- poorly immunogenic. with the RTS,S/AS02 candidate in a supported investigators have carried out Phase II trial, although additional studies a number of studies and clinical trials in will be required to verify these results in Mali and Ghana, and plans are now younger children and in different epidemi­ being made for additional clinical trials

MALARIA 101 in the years to come. sample sizes when evaluating malaria Beginning in late 2004, a Malaria vaccines. On the other hand, the appar- Vaccine Technology Roadmap initiative, ent efficacy of vaccines may be greater organized by the MVI with support in areas in which control programs have from the Wellcome Trust and the Bill been able to reduce but not eliminate and Melinda Gates Foundation, brought malaria transmission. together investigators from both developed and developing countries as well as representatives of the broader malaria vaccine research and development com­ munity, including research funding agencies, economic development agencies, and philanthropies. Through a series of meetings and workshops, these groups were asked to identify challenges and hurdles confronting malaria vaccine development and to establish a set of shared priorities and objectives to further accelerate malaria vaccine development. The Roadmap thus offers a context in which to develop improved collabora­ tive efforts, and these efforts are already under way. In late 2005, NIAID and the WHO Initiative for Vaccine Research jointly sponsored a meeting on stan­ dardization of assays for development of candidate malaria vaccines. With an increasing number of groups becoming involved in malaria vaccine research and development, there are new opportunities for collaboration and synergy to accelerate the pace of malaria vaccine development. In addi­ tion, there are new malaria intervention and control efforts, including the Roll Back Malaria Partnership, the Intermittent Preventive Treatment in Infants Consortium, the Global Fund for AIDS, Tuberculosis and Malaria, and the U.S. President’s Malaria Initiative. These activities are likely to impact future clinical and field studies of malaria vaccines, and raise both new opportunities and challenges. Effective control programs, for example, may call for adaptations in study design and

102 THE JORDAN REPORT 2007 Severe Acute Respiratory Syndrome (SARS)

Background

n the spring of 2003, the world first learned of an outbreak of a newly I recognized atypical pneumonia that was named severe acute respiratory syn­ drome (SARS). Believed to have originated in the Guangdong province of China in late 2002, SARS quickly spread to Hong Kong, Taiwan, Singapore, Canada, and Vietnam and, ultimately, to a total of 29 countries. There were 74 probable cases in the United States. Overall, more than 8,000 patients were affected, with 774 fatalities in less than one year. The speed with which the global health community responded to SARS was unparalleled. Shortly after SARS Coronaviruses are a group of viruses that have a halo, or crown-like (corona) first emerged, the disease’s etiological appearance when viewed under a microscope. Courtesy of CDC / Dr. Fred Murphy agent was identified as a novel coron­ avirus called SARS-CoV, which was determined to be phylogenetically distinct family members. Higher mortality was natural reservoir of virus, with the civet from previously known human and ani­ observed in older patients, with more serving as the intermediate host. Both mal coronaviruses. Characterization of than 50 percent of fatalities occurring in animals are sold in Chinese marketplaces. the virus indicated that it was a single people 65 years of age or older. Children In the months after the disease first stranded, positive sense RNA virus, with were the least likely to acquire the disease. emerged, the clinical syndrome was a large genome of 29.7 kilobases. The likely immediate sources of characterized, the etiological agent was SARS-CoV was discovered to be SARS-CoV that initiated the outbreak identified, diagnostic tests were devised, primarily transmitted from person to were exotic animals from Guangdong and the virus’ genome was completely person by close contact with large respi­ marketplaces. SARS-CoV-like viruses, sequenced. The speed of scientific under­ ratory droplets. Symptoms of illness ini­ with 99 percent identity to human standing and information exchange, tially included flu-like symptoms, with strains, were isolated primarily from combined with critical public health fever, cough, body aches, and malaise Himalayan palm civets as well as other measures such as patient isolation and after an incubation period ranging from marketplace animals. From two inde­ infection control, eventually led to out­ 3 to 10 days. Most patients developed pendent field studies, another animal break containment. In July 2003, the World pneumonia and more than 60 percent of species, the Chinese horseshoe bat, was Health Organization officially declared chest X-rays showed infiltrates. Up to 20 subsequently found to harbor a SARS­ the outbreak over. Since July 2003 there percent of individuals had diarrhea. CoV-like virus that was 93 percent have been four separate laboratory- Epidemiological investigation identical to human SARS-CoV. Since acquired SARS infections—one each in showed that SARS disproportionately SARS-CoV-like virus was not found in Singapore and Taiwan, and two in China. affected health-care workers and other farm-raised palm civets, it is concluded In addition, two individuals in southern close contacts of SARS-patients, such as that the horseshoe bat may serve as the China contracted SARS in December

SEVERE ACUTE RESPIRATORY SYNDROME 103 virus) genetically modified to express the SARS S protein.

Understanding SARS NIAID-supported scientists have made significant advances in understanding SARS-CoV and its pathogenicity. For example, researchers discovered that the papain-like protease of SARS-CoV has a deubiquitinating enzyme activity that regulates location and stability of cellu­ lar proteins, and determined its three- dimensional structure. This work may lead to the design of small molecule inhibitors of this essential SARS enzyme. Researchers have also identified and Researchers have identified the Rhinolophus macrotis horseshoe bat as a natural reservoir of SARS Co-V and the civet as an intermediate host. Bat image courtesy of Dr. Tigga Kingston, Texas Tech University. Palm civet characterized the lung receptor mole­ image courtesy of Dr. Wayne Marasco / Harvard Medical School cule, ACE2, to which the S protein adheres. Regions of interaction between the S protein and ACE2 were mapped 2003 after being exposed to the virus in binant S protein subunit vaccine. S protein and characterized, and the domains of a restaurant. is used by the virus to attach to lung cells. the S protein necessary for viral infection There have been no new SARS cases A contract was also awarded to support were determined. These findings are reported since April 29, 2004. While the the generation of a monoclonal antibody particularly important in the design of 2003 outbreak has not been repeated, to the S protein, which has subsequently improved vaccines and therapeutics. the threat has not disappeared. Because demonstrated both prophylactic and Scientists have learned that the entry of an animal reservoir of the precursor therapeutic properties in animals. After SARS-CoV is blocked by inhibitors of virus exists in nature, an effective vaccine these experimental vaccines and the the endosomal protease cathepsin L, and and/or therapeutic is still needed should monoclonal antibody are manufactured a secondary receptor that augments SARS reemerge. While the global health and preclinical data generated and summa­ infection, L-SIGN, was also identified impact was substantial, that pales in rized, NIAID plans to test them in clini­ and characterized. comparison to the economic impact with cal trials conducted by its Vaccine and Researchers in NIAID’s Laboratory respect to travel, tourism, and service Treatment Evaluation Units. of Infectious Diseases (LID) studied the industries. In addition, NIAID-supported replication of SARS-CoV in mice, ham­ investigators are pursuing a SARS vaccine sters, and non-human primates (NHPs) Current Status of Science based on soluble S-protein expressed in and established that intranasally admin­ Because it is not known which type of mammalian cells, as well as a vaccine istered SARS-CoV replicated efficiently vaccine will be most effective against based on baculovirus-expressed S protein in respiratory tissues. In BALB/c mice SARS CoV, the National Institute of combined with a novel adjuvant for and hamsters, the virus replicated to levels Allergy and Infectious Diseases (NIAID) intranasal delivery. An alphavirus replicon that permit an evaluation of vaccines, is supporting several different vaccine against SARS is under develop­ immunotherapies, and antiviral drugs. approaches to vaccine development. ment, as is a vaccine based on SARS In addition, further studies in mice and In 2003, NIAID awarded contracts proteins expressed in virus-like particles. hamsters demonstrated that primary for the production of experimental, Alternate strategies being developed infection provides protection from inactivated, whole virus SARS vaccines include a peptide-based vaccine re-infection and that antibodies alone as well as for the production of a recom­ approach, and a rhabdovirus (rabies can block against viral replication. This

104 THE JORDAN REPORT 2007 work suggests that vaccines that induce vaccine is composed of a modified piece Several other efforts are ongoing neutralizing antibodies, and strategies of DNA that encodes the S protein of throughout the world in private industry for immunoprophylaxis or, perhaps, SARS-CoV and is expected to stimulate to advance the development of a SARS immunotherapy are likely to protective immunity in humans. A Phase vaccine. For example, in May 2004, 36 be effective in combating SARS. LID I open-label clinical study to evaluate volunteers in Beijing, China, received an scientists have collaborated with scientists safety, tolerability, and immune response inactivated SARS vaccine produced by a at academic institutions to demonstrate was initiated in December, 2004. The Beijing-based company, Sinovac the efficacy of monoclonal antibodies study enrolled 10 healthy volunteers, Biotech. Most volunteers receiving this against the spike protein of SARS-CoV ages 18 to 50, and administered 4 mg vaccine generated an antibody response in prevention and treatment of SARS- DNA vaccinations at three one-month and no obvious side effects were noted. associated disease in hamsters. intervals. Interim study results indicate A larger Phase II study is planned. Further, while the LID investigators that the vaccine is well tolerated with no observed no clinical illness in young or mild systemic or local mice, hamsters, or NHPs, because reactogenicity, and no advanced age has been associated with serious adverse events. poorer outcomes, and greater mortality NIAID-supported in SARS patients, the investigators scientists have also made examined whether aged mice might be significant advances susceptible to disease. They found that that have improved SARS-CoV-infected aged mice demon­ understanding of SARS- strated signs of clinical illness that CoV. For example, resolved by day 7 post-infection. The researchers are elucidat­ virus-infected aged mice mounted an ing the role of SARS- adaptive immune response to infection; CoV non-structural however, in contrast to young mice, they proteins to enhance also mounted a proinflammatory knowledge of the inter­ cytokine response early post-infection. action of SARS-CoV This work demonstrated in animals an proteins with the medi­ age-related susceptibility to SARS that ators of the innate parallels the human experience. immune system. In The LID scientists have also collabo­ addition, NIAID con­ rated with other scientists at the National tractors have screened Institutes of Health, as well as researchers 100,000 potential at academic institutions and in industry, antiviral drugs and to evaluate a number of candidate SARS- other compounds for CoV vaccines, including inactivated, activity against SARS- The receptor binding domain (RBD) of the SARS-CoV S protein depicted cocrystallized with human ACE2. Courtesy of Dr. Michael Farzan / subunit, vectored, and DNA vaccines, in CoV. Several compounds Harvard Medical School animal models. have demonstrated antivi­ Researchers at NIAID’s Dale and ral activity and are being tested in animal Betty Bumpers Vaccine Research Center model systems. Meanwhile, a full length are working in partnership with Vical, cDNA clone of infectious SARS-CoV Inc., to manufacture an experimental was generated by reverse genetics SARS vaccine that has been shown to through a systematic assembly approach. prevent the SARS-CoV from replicating This valuable tool and its variants were in laboratory mice. Instead of using a rapidly generated and utilized for repli­ weakened or inactivated virus, the new cation and pathogenesis studies.

SEVERE ACUTE RESPIRATORY SYNDROME 105 Genome map of SARS-CoV. Courtesy of Dr. Wayne Marasco / Harvard Medical School

Challenges and Opportunities models that better mimic human disease While the need is clear and the re-emer­ with respect to clinical course and gence of SARS likely, the cost, length of symptoms. Improved models will help time for needed product development, and to better understand the pathophysiol­ uncertain demand result in unfavorable ogy of disease, including innate and economic conditions for commercial adaptive immune responses and vaccine and therapeutic development. immunopotentiation, and help to move Better understanding of several phe­ vaccines and therapeutics through nomena is needed, including how the advanced development to licensure. SARS virus can infect animals without In the development of SARs thera­ detrimental effect and how it passes peutics and next-generation vaccines, from one animal species to another additional work is needed to determine (horseshoe bat to civet) as well as from the structure/function relationships of animal to human. Advances concerning critical enzymes and structural proteins. these topics could also apply to the Once these are better understood, many other viruses that pass from ani­ design of improved small molecule and mals to humans. protein inhibitors is possible. Preliminary in vitro and animal A long-term public health strategy studies indicate that initial exposure to that can control future SARS outbreaks SARS-CoV could exacerbate disease will require effective vaccines and thera­ resulting from a subsequent exposure; peutics, as well as plans to limit the this phenomenon, called antibody- impact on the transportation system, on dependent enhancement, has been seen health care and service workers, and on with respiratory syncytial virus, dengue the elderly. virus, and Feline Infectious Peritonitis virus. Improved small and large animal models for SARS are needed, particularly

106 THE JORDAN REPORT 2007 References 17. Taylor DR, Obstacles and advances in SARS 1. He Y et al., Cross-neutralization of human vaccine development, Vaccine 2006; 24:863­ and palm civet severe acute respiratory syn­ 871. drome coronaviruses by antibodies targeting 18. Weiss SR, Navas-Martin S, Coronavirus patho­ the receptor-binding domain of spike protein, genesis and the emerging pathogen severe J Immunol 2006;176:6085-6092. acute respiratory syndrome coronavirus, 2. Holmes KV, Structural biology. Adaptation of Microbiol Mol Biol Rev 2005;69:635-664. SARS coronavirus to humans, Science 19. Yang ZY and Werner HC, Evasion of antibody 2005;309:1822-1823. neutralization in emerging severe acute respi­ 3. Jeffers SA et al., CD209L (L-SIGN) is a recep­ ratory syndrome coronaviruses, Proc Natl tor for severe acute respiratory syndrome Acad Sci USA 2005;102:797-801. coronavirus, Proc Natl Acad Sci USA 20. Yount B and Curtis KM, Reverse genetics with 2004;101:15748-15753. a full-length infectious cDNA of severe acute 4. Kong WP et al., Modulation of the immune respiratory syndrome coronavirus, Proc Natl response to the severe acute respiratory syn­ Acad Sci USA 2003;100:12995-13000. drome spike glycoprotein by gene-based and 21. Zhou Z et al., A recombinant baculovirus­ inactivated virus immunization, J Virol expressed S glycoprotein vaccine elicits high 2005;79:13915-13923. titers of SARS-associated coronavirus (SARS- 5. Li W et al., Angiotensin-converting enzyme 2 CoV) neutralizing antibodies in mice, Vaccine is a functional receptor for the SARS coron­ 2006;24:3624-3631. avirus, Nature 2003;426:450-454. 6. Li W et al., Bats are natural reservoirs of SARS-like coronaviruses, Science 2005;310:676-679. 7. Li W et al., Animal origins of the severe acute respiratory syndrome coronavirus: insight from ACE2-S-protein interactions, J Virol 2006;80:4211-4219. 8. Peiris JS et al., Severe acute respiratory syn­ drome, Nat Med 2004;10:S88-S97. 9. Perlman S and Dandekar AA, Immunopathogenesis of coronavirus infec­ tions: implications for SARS, Nat Rev Immunol 2005;5:917-927. 10. Plant EP et al., A three-stemmed mRNA pseudoknot in the SARS coronavirus frameshift signal, PLoS Biol 2005;3:e172. 11. Ratia K et al., Severe acute respiratory syn­ drome coronavirus papain-like protease: Structure of a viral deubiquitinating enzyme, Proc Natl Acad Sci USA 2006;103:5717-5722. 12. Roberts A et al., Therapy with a severe acute respiratory syndrome-associated coronavirus­ neutralizing human monoclonal antibody reduces disease severity and viral burden in golden Syrian hamsters, J Infect Dis 2006;193:685-692. 13. Simmons G et al., Inhibitors of cathepsin L prevent severe acute respiratory syndrome coronavirus entry, Proc Natl Acad Sci USA 2005;102:11876-11881. 14. Simmons G et al., Characterization of severe acute respiratory syndrome-associated coron­ avirus (SARS-CoV) spike glycoprotein-medi­ ated viral entry, Proc Natl Acad Sci USA 2004;101:4240-4245. 15. Spruth M, et al., A double-inactivated whole virus candidate SARS coronavirus vaccine stimulates neutralising and protective anti­ body responses, Vaccine 2006;24:652-661. 16. Subbarao K, Roberts A, Is there an ideal ani­ mal model for SARS? Trends in Microbiology (2006);14:299-303.

SEVERE ACUTE RESPIRATORY SYNDROME 107 108 THE JORDAN REPORT 2007 Streptococcus Pneumoniae

neumococcus (Streptococcus There are more than 90 serotypes of of pneumococcal transmission. In fact, pneumoniae) is a common bacte­ S. pneumoniae based on variations in its the herd immunity effect observed in P rial pathogen in adults worldwide capsular polysaccharide. Currently 2003 was actually twice as large as the and one of the foremost causes of morbid­ licensed vaccines are composed of cap­ direct protective effect. Of the 29,599 ity and mortality in infants and children sular polysaccharide alone (containing vaccine-type infections prevented by in developing countries. Pneumococci 23 capsular serotypes) or in conjugated Prevnar in 2003, just 9,140 were due to are also responsible for many deaths form where the polysaccharide is chemi­ direct protective effects. The rest of the from infectious diseases in the elderly, cally linked to a protein carrier. Prevnar, prevented infections were the result of and cause the bulk of ear infections in a licensed pneumococcal conjugate vac­ herd immunity. This indirect effect has young children. They are a significant cine, contains 7 of the more clinically carried over into other populations as cause of meningitis in young children important serotypes in the United well. The greatest declines in both vac­ and the elderly. In much of the develop­ States, but newer versions under evalua­ cine-type and overall pneumococcal ing world, Streptococcus pneumoniae is a tion contain up to 13 capsular types, infections occurred in individuals who leading cause of fatal respiratory infec­ many of which are responsible for inva­ were at least 65 years of age. tions in children less than 5 years of age, sive disease in developing countries. Between 1998 and 2003, pneumo­ resulting in more than 800,000 deaths per While these conjugate vaccines are prov­ coccal invasive disease among adults year in this age group. ing to be efficacious against disease and over the age of 50 decreased by more S. pneumoniae is a common bacterium are making a significant impact on pub­ than 50 percent for serotypes included that is present in the nasopharynx of lic health, their success may be limited in the Prevnar vaccine. In addition, the many children and some adults, where it by economic and clinical factors. overall incidence of serious pneumococ­ causes no harm to its host, but can be In just 3 years following the wide­ cal infections dropped 28 percent. transmitted to others. If it moves beyond spread introduction of Prevnar in the Although there has been an increase in the nasopharynx, however, it can cause United States in 2000, there was a 94 the use of the licensed 23-valent pneu­ ear infections or invasive disease such as percent reduction in the rate of invasive mococcal polysaccharide vaccine in the pneumonia or meningitis. Although ear pneumococcal disease among vaccinated elderly over the past several years, it is infections in young children generally children younger than 5 years of age for unlikely that this would account for do not lead to meningitis or other serious serotypes associated with the vaccine. such marked declines. Rather, a good pneumococcal diseases, they do result in Children receiving Prevnar showed proportion of the decrease in invasive costly clinic visits and much lost work reduced nasopharyngeal carriage of vac­ disease among adults can be attributed for parents. Because of its ability to cine strains, especially for those strains to the use of the Prevnar vaccine in chil­ infect the very young, the very old, and that were most resistant to antimicrobial dren, further supporting the notion of a the immunodeficient, pneumococcus agents. A very interesting and unantici­ herd effect. Overall, the routine use of has one of the largest public health and pated finding is the indirect (herd) Prevnar has greatly decreased the inci­ economic impacts of any infectious dis­ effect of the vaccine in reducing the risk dence of pneumococcal disease caused ease in the United States. Patients recov­ of nasopharyngeal colonization in by antibiotic-resistant pneumococci in ering from viral infections such as unvaccinated children in close contact the vaccinated population and reduced measles or influenza and those already with immunized playmates. Because adult transmission. afflicted with chronic diseases such as approximately 75 percent of children in There have been numerous articles human immunodeficiency virus (HIV) the United States have been vaccinated in the literature citing other beneficial constitute especially susceptible hosts in with Prevnar, some of the decline in the clinical effects following the licensure of whom mortality is high. overall infection rate appears to reflect Prevnar. One study that looked at an indirect effect due to the interruption 63,000 hospitalized adults showed that

STREPTOCOCCUS PNEUMONIAE 109 vaccinated patients were less likely to die serotypes are capable of becoming pneumococcal infections, but has been while in the hospital than unvaccinated resistant to antibiotics. Furthermore, the shown to be approximately 60 percent patients or patients with unknown increased prevalence of non-vaccine efficacious in preventing invasive disease vaccination status. These vaccinated serotypes, due to the selective pressure in adults. One of the major concerns patients were less likely to develop respi­ induced by the extensive use of the con­ associated with this vaccine is its inabil­ ratory failure, heart attacks, or kidney jugate pneumococcal vaccine, may play ity to induce a T-cell dependent mem­ failure and their average hospital stay a role in establishing highly virulent ory response. It is for this reason that was two days shorter than that of unvac­ strains of pneumococci that cause more the vaccine is not recommended for use cinated patients. Another study involved invasive forms of disease. Thus, there is in children less than two years of age. a Phase III trial conducted in Finnish a need to develop new pneumococcal Two-year-old children immunized first infants. Children receiving 3 doses of vaccines that offer broader coverage and with a pneumococcal conjugate vaccine the 7-valent pneumococcal conjugate protection from all serotypes associated and then a pneumococcal polysaccha­ vaccine before 6 months of age and a with the organism. Such an effort is best ride vaccine demonstrated higher anti­ booster dose before 15 months of age exemplified by the development of com­ body concentrations to each of the showed (1) a 7 percent reduction in the mon surface protein vaccines that can serotypes contained in the conjugate total number of episodes of middle ear provide complete protection to all pneu­ vaccine than did children who received a infection; (2) a 34 percent reduction in mococcal serotypes and age groups. This Haemophilus influenzae type b (Hib) pneumococcal acute otitis media; and work continues on many fronts with conjugate vaccine as a control. Infants (3) a 57 percent reduction in acute otitis emphasis on such proteins as PspA, primed with the pneumococcal polysac­ media caused by the pneumococcal PspC, other choline-binding proteins, charide vaccine had considerably lower serotypes included in the Prevnar vaccine. PsaA, autolysin, pneumolysin, neu­ antibody responses when subsequently Even though antimicrobial therapy raminidase, and IgA1 protease, along immunized with the same vaccine. has resulted in reduced morbidity and with several additional proprietary anti­ These results suggest that the pneumo­ mortality rates associated with invasive gens. The limited number of serotypes coccal conjugate vaccine is capable of pneumococcal disease, the prevalence of that can be included in a single dose of effectively priming the immune system antimicrobial resistance among S. pneu­ conjugate vaccine, along with special­ of infants to induce an anamnestic T- moniae continues to increase worldwide. ized needs for incorporating specific cell response to a subsequent dose of Thus, the reduction in resistant infec­ serotypes depending on where in the pneumococcal polysaccharide. tions following the use of Prevnar repre­ world the vaccine will be administered, Along these same lines, the efficacy sents one of the most significant poses certain restrictions for its general of the pneumococcal polysaccharide benefits of the vaccine, which translates use on a global scale. A widely useful vaccine in immunocompromised adults into fewer complications due to antibiotic vaccine will probably have to contain a is considerably less than that observed resistance and fewer treatment failures. cocktail of several pneumoncoccal among immunocompetent individuals One of the major drawbacks or virulence factors, each of which will of a similar age. In addition, among unwanted effects of the introduction of stimulate the immune system to block adults 65 years of age and older who Prevnar into the routine immunization a specific function, such as attachment receive a recommended dose of the 23­ schedule has been the increased preva­ to human host cells or evasion of valent pneumococcal polysaccharide lence of colonization and disease caused human immune responses. vaccine, there is a steady decline in (1) by non-invasive strains not associated Since 1989, the 23-valent pneumo­ the antibody response to the majority of with the vaccine. This is referred to as coccal polysaccharide vaccine has been the vaccine antigens over time; and (2) “bacterial replacement.” Several routinely recommended for use in the efficacy of the vaccine with increas­ serotypes—in particular 11, 15, and adults over the age of 65 in addition to ing age at the time of vaccination. 19A—have increased substantially and individuals at high risk of pneumococ­ Because of the waning efficacy post- become prominent players in disease- cal infections as a result of certain immunization and the increased risk for related situations. This phenomenon has chronic illnesses. This vaccine has varied disease, many physicians have routinely created much concern because these efficacy against all manifestations of re-immunized their elderly patients with

110 THE JORDAN REPORT 2007 the 23-valent vaccine approximately During the past year, an important every 5 years. Unfortunately, these set of results was presented from a vac­ revaccinated individuals generally show cine efficacy trial conducted in The a reduced immune response compared Gambia and supported by a broad coali­ to their initial response when first tion of international partners (see The immunized with the vaccine. To over­ Gambia Pneumococcal Vaccine Trial). come this hypo-responsive state, several The results revealed that deaths from clinical trials were conducted to evaluate pneumococcal infection in rural settings the benefit of first immunizing the eld­ were preventable and that pneumococ­ erly with a conjugate pneumococcal vac­ cal vaccination could prevent serious cine followed by revaccination with the infections even under conditions where 23-valent polysaccharide vaccine. Data the burden of disease is high, offering from studies that use this approach look great promise for improving the health very promising and suggest that estab- and saving the lives of children in disad-

The Gambia Pneumococcal Vaccine Trial found there were 37 percent fewer cases of pneumonia in children who received the vaccine. Courtesy of PneumoADIP / Photograph by Selena Haylock

lishing a T-cell-dependent immune vantaged populations. Efforts to response early on, when the risk of broaden the availability of these multi­ disease is high, helps promote a more valent pneumococcal conjugate vaccines robust immune response and a reduced in developing countries are now under risk of hypo-responsiveness to subse­ way and will require considerable sup­ quent immunization(s) with the port from the international community. 23-valent vaccine.

STREPTOCOCCUS PNEUMONIAE 111 THE GAMBIA PNEUMOCOCCAL VACCINE TRIAL

Each year, pneumococcal pneumonia and meningitis cause 800,000 to 1 million deaths in children under the age of 5. Ninety percent of these deaths occur in developing countries, where pneumococcal meningitis kills or disables 40 percent to 75 percent of the children who contract it.

From 2000-2004, a team of scientists led by the British Medical Research Council vaccinated and followed more than 17,000 young children in The Gambia to determine whether a pneumococcal conjugate vaccine could substantially reduce death and serious illness from Streptococcus pneumoniae. This randomized, double-blind, placebo- controlled trial was supported by the National Institute of Allergy and Infectious Diseases along with a coalition of international partners.

The primary objective of the trial was to examine the ability of a nine-valent pneumococcal conjugate vaccine to reduce the morbidity and mortality from pneumococcal diseases in a rural setting where child mortality was high and access to healthcare was limited.

This was the first major randomized, controlled vaccine clinical trial in nearly 20 years to show significant reduction in overall child mortality.

● The vaccine used was 77 percent effective in preventing invasive pneumococcal infections caused by the vaccine serotypes.

● There were 37 percent fewer cases of pneumonia in the children who received the vaccine.

● The vaccine significantly reduced the need for hospitalization: children receiving the pneumococcal vaccine had 15 percent fewer hospital admissions than those who did not.

● The vaccine reduced childhood mortality by 16 percent in children who received the pneumococcal conjugate vaccine.

Article: Cutts FT et al., Efficacy of nine-valent pneumococcal conjugate vaccine against pneumonia and invasive pneumococcal disease in The Gambia: randomised, double-blind, placebo-controlled trial, Lancet 2005;365:1139-1146.

112 THE JORDAN REPORT 2007 Tuberculosis

Background strains of Mycobacterium tuberculosis the lack of integration of TB and human that are resistant to many of the available immunodeficiency virus (HIV) health- espite significant advances in drugs to treat TB have increased aware­ care services in areas where the spread tuberculosis (TB) research and ness that this ancient disease has the of tuberculosis is closely linked to the D improvement in treatment potential to re-surge in many countries, HIV co-epidemic; the lack of availability strategies worldwide, the disease remains including the United States and lead to of rapid and sensitive diagnostics; the one of the leading killers in infectious significant public health issues. Failure development of multi-drug resistant disease. Although TB is usually curable, to contain this disease can be attributed (MDR) and extensively drug resistant tuberculosis continues to spread across to a number of factors including the (XDR) TB that are difficult to treat and the globe and claims close to two mil­ need for a more comprehensive tuber­ remains transmissible; and the lack of a lion lives each year. Recent increases in culosis treatment and care infrastructure highly effective vaccine. drug resistant TB and the appearance of in endemic, resource-limited countries; In most cases, infection with M. tuberculosis results in an asymptomatic colonization that is controlled by the immune system (latent or persistent infection). Weakening of the immune system, as is the case in persons also infected with HIV, can result in reactiva­ tion of bacterial growth and progression from latent infection to active tubercu­ losis. Patients with active tuberculosis are treated with combination chemotherapy for six to nine months. The length of this regimen, combined with drug-related adverse events, fre­ quently leads to noncompliance and treatment failures, which in turn can result in the development and spread of drug-resistant tuberculosis. Proactive identification of patients with active TB and rapid identification of MDR and XDR TB, followed by directly observed drug treatment with the most appropri­ ate drug regimen (directly observed treatment, short course [DOTS]), com­ bined with effective vaccination schedules, are considered the most likely means by which tuberculosis could be eliminated as a global public health burden. The currently available tuberculosis vaccine, Mycobacterium bovis Bacille Sadhne, a 60-year-old tuberculosis patient in an East Delhi clinic. According to the World Health Organization, the largest number of new TB cases in 2004 occurred in Southeast Asia, which accounted for 33 percent of Calmette-Guérin (BCG), was developed cases globally. © World Lung Foundation / Photograph by Gary Hampton

TUBERCULOSIS 113 almost 100 years ago. Worldwide, a vari­ ety of BCG strains are available and widely delivered under the World Health Organization (WHO) Expanded Programme on Immunization. One BCG vaccine strain (Tice) is licensed in the United States against tuberculosis but is not recommended for general use. Despite its lack of consistent, reproducible efficacy in clinical trials to prevent adult pulmonary tuberculosis in various regions of the globe, BCG is the most widely administered vaccine worldwide and appears to protect against childhood complications and death in children, although few controlled clinical studies A scanning electron micrograph (SEM) depicting some of the ultrastructural details seen in the cell wall configuration of a number of Gram-positive Mycobacterium tuberculosis bacteria. Courtesy of CDC / Janice Carr have been conducted to confirm this observation. Although vaccination with BCG has been insufficient to prevent A sudden spike in new cases was reported sequence of M. tuberculosis and other adult pulmonary tuberculosis, which is between 1986 and 1992. This resurgence mycobacterial species, and development primarily responsible for the continued of tuberculosis was attributable largely of microbiologic and genetic tools that spread of the disease, it is not known to deteriorating public health infrastruc­ helped dissect the interaction of the how many cases of tuberculosis would ture and was also coincident with the pathogen with the host immune occur globally without BCG vaccine. HIV epidemic. In 1993, tuberculosis was response and aided in vaccine develop­ Development of more effective vac­ declared a global health emergency by ment and evaluation. Readily available cines to prevent either infection with M. the WHO. Following these events, microarrays have facilitated the investi­ tuberculosis or progression to active dis­ awareness of the global impact of tuber­ gation of differential expression of host ease remains a priority for the National culosis increased and led to the realiza­ and pathogen genes at various stages of Institute of Allergy and Infectious tion that improving our understanding infection and disease, and have con­ Diseases (NIAID). Since 1998 when the of tuberculosis pathogenicity and host- tributed to our understanding of the U.S. Department of Health and Human pathogen interaction is a prerequisite mechanisms driving tuberculosis patho­ Services’ Advisory Council for for identifying better ways to diagnose, genicity. These efforts have also been Elimination of Tuberculosis (ACET), the prevent, and treat this disease. Research aided by the establishment of structural U.S. National Vaccine Program Office, funding has steadily increased since genomics consortia and collection of and NIAID convened a workshop to 1992, and NIAID has developed a com­ data using a systems biology approach, develop the Blueprint for Tuberculosis prehensive research program to stimu­ activities that have been funded by Vaccine Development, several promising late and support all aspects of NIAID and through National Institutes vaccine candidates have been identified, tuberculosis science and product devel­ of Health (NIH) initiatives. some of which are now being evaluated opment. This funding has contributed Significant effort has been expended in humans in clinical trials. significantly to the current advances in to develop relevant animal models of M. tuberculosis vaccine development, tuberculosis infection that more closely State of the Science in specifically in the areas of TB immunol­ mimic human disease, in order to pre­ Tuberculosis Vaccine ogy, pathogenicity, and molecular dict vaccine efficacy from animal stud­ Development aspects of host-pathogen interaction. ies. From that effort it became clear that Until the early 1980s, tuberculosis in the Research was also boosted in recent the pathogenesis of tuberculosis varies United States had been steadily declining. years by publication of the genome among different animal species and that

114 THE JORDAN REPORT 2007 a number of dynamic immunological Several candidates that demon­ Although tuberculosis vaccine research factors modulate disease outcome after strated protection against infection with has made tremendous advances over the infection with M. tuberculosis. Through M. tuberculosis in small animal models last 10 to 15 years, a number of critical the development and refinement of equally well or better than BCG have questions remain to be answered. These these models, which now extend from entered human clinical trials. These are answers will likely provide the keys to rodents (mice and guinea pigs) to rab­ the first studies of new, engineered faster tuberculosis vaccine development. bits and non-human primates, tuberculosis vaccine candidates since the ● Why are some individuals able to con­ researchers continue to gain insight into introduction of BCG in 1921, with the tain infection with M. tuberculosis and immunological and microbiologic fac­ exception of current studies using contain this pathogen as a latent, tors that are involved in developing Mycobacterium vaccae as a vaccine to asymptomatic infection while others active disease versus asymptomatic prevent disseminated tuberculosis in progress to active disease, and what infection. This enhanced understanding AIDS patients. This new generation of does it mean from the standpoint of of small animal models of tuberculosis clinical candidates includes a recombi­ bacterial physiology and host has enabled the testing of more than 100 nant BCG vaccine expressing the 30 kD response? To answer this question, new vaccine candidates and approaches major secretory protein of M. tuberculo­ longitudinal human studies of M. over the past nine years. These candi­ sis, Ag85B (rBCG30); a fusion protein tuberculosis infection are needed to dates are representatives of a diverse set composed of immuno-dominant M. define parameters that can then be of vaccine classes and include recombi­ tuberculosis peptides (Mtb72f); and a modeled in animals to derive nant BCG and live attenuated M. tuber­ boost strategy using Ag85A expressed approaches and solutions to prevent­ culosis strains; various other live vectors from a viral vector after primary BCG ing progression to active disease. (bacterial and viral); and DNA, protein, vaccination. Additionally, clinical studies ● What factors can serve as markers of and peptide subunit vaccines. It is rec­ are being planned to better define the immunoprotection in humans to ognized that due to the benefit that immune protection elicited by BCG in allow assessment of immunogenicity BCG provides against pediatric TB, as pediatric populations, as well as whether in clinical trials? Only with the aid of well as its collateral efficacy against lep­ alternative means of administering BCG data from human vaccine trials will rosy, viable vaccination strategies will would enhance the spectrum of researchers be able to refine animal likely have to include neonatal BCG vac­ immune response elicited by this vac­ models and identify which immune cination boosted with novel vaccines at cine. Overall, the research community is parameters need to be established for a later stage in life with the intent to developing a comprehensive approach further vaccine development. For reactivate immunological memory and to designing improved vaccination these reasons, it is critical that vaccine protect against primary infection and/or strategies for tuberculosis. Currently, it candidates are quickly evaluated for reactivation of latent infection. Because is estimated that combination safety and efficacy in human trials, about one-third of the world’s popula­ approaches will be needed to produce and any subsequent findings used to tion is thought to harbor asymptomatic protective immune responses in adult devise more targeted vaccine strategies. infection with M. tuberculosis, and may populations. ● What is the importance of co-infections therefore serve as a reservoir for new and co-morbidities in patients at high cases of tuberculosis, prevention of Challenges and Opportunities risk for M. tuberculosis infection and reactivation of disease may prove critical for Developing a Vaccine for progression to active disease? Will a to curb the spread of tuberculosis. This Tuberculosis vaccine that was developed in labora­ consideration is especially important in The majority of research toward new tory animals be effective in these real- regions where there is a high prevalence and improved vaccines has only life settings? How will persons already of HIV co-infection, which increases the occurred during the last decade. Hence, infected with M. tuberculosis respond chances of developing active disease little historical experience in tuberculo­ to vaccination? from 1 in 10 over the course of a per­ sis vaccinology is available that can be ● What role will diagnostics play in the son’s life to 1 in 10 per year. used as guidance for developing or development of tuberculosis vaccines? improving new tuberculosis vaccines. Since delayed-type hypersensitivity

TUBERCULOSIS 115 testing is not a reliable measure of immunoprotection. In order to to stim­ Vaccine and Treatment Evaluation Units infection or cure, identification of the ulate product development against this provide clinical trials infrastructure that appropriate patient population re-emerging disease, applied research in is accessible to TB projects that evaluate remains a challenge. For this reason, tuberculosis is included under Category vaccine candidates and conduct studies diagnostics development needs to C of NIAID’s Biodefense Research on surrogate markers of protection. remain closely coupled with immunol­ Program. In addition, NIAID provides Knowledge gained from research ogy and vaccinology research to pro­ resources through its genomics and over the past 14 years has matured to duce, in parallel, essential tools for the bioinformatics programs that are also the level where tangible product candi­ successful conduct of clinical evaluation available to the tuberculosis research dates are entering clinical trials. of candidate vaccines. community. It is recognized that the Development needs for an imple­ ● How does BCG work in children? resurgence of tuberculosis, and especially mentable vaccine are being discussed in This is a currently understudied but MDR TB and now also XDR TB, places a the StopTB Partnership’s Global Plan to important aspect of vaccine develop­ tremendous economic burden on Stop TB, 2006–2015. This publication ment. Little is known about general or affected countries, with the potential to not only attests to the continued need tuberculosis-specific differences in re-emerge in the United States. for new vaccines against TB but also immune response and vaccine efficacy NIAID’s Tuberculosis Research recognizes the need for continued fund­ among infants, children, and adults. It Materials and Vaccine Screening ing for and contributions from funda­ is recognized that the clinical presen­ contract at Colorado State University mental and translational science, both of tation of tuberculosis is different in (www.cvmbs.colostate.edu/microbiology/ which are heavily supported by NIAID. young children from that in adults tb/top.htm) provides high-quality Although the field of tuberculosis vac­ and that BCG efficacy differs signifi­ research reagents and vaccine testing cine development has produced a rich cantly in these populations. services in small animal models to array of potential candidates and many ● Because it will not be ethical to con­ researchers worldwide. The NIAID- donors are continuing to support pre­ duct a placebo controlled clinical trial supported Tuberculosis Animal Research clinical research, a clear funding and with an experimental vaccine, what and Gene Evaluation Taskforce (TARGET) “interest” gap continues to exist for treatment regimens will the patient at Johns Hopkins University (http:// non-academic production, safety assess­ populations receive during this trial? webhost.nts.jhu.edu/target) bridges the ment, and readying of vaccine candidates How will this influence the ability to gap between identification of genes that for clinical development. assess efficacy of the vaccine or even may play a role in interaction between Despite the many challenges remain­ the outcome measures of the trial? host and pathogen and actual determi­ ing in tuberculosis vaccine development, How can studies be designed to mini­ nation of the biological function of a new sense of optimism is permeating mize the sample size and study dura­ these genes. Resources for researchers the tuberculosis research and public tion? Who will fund such challenging working on infectious agents under health communities as recent research and time-consuming studies and Category C of NIAID’s Biodefense advances result in novel vaccine candidates commercialize a vaccine? Research Program are available to help entering human trials. advance promising preclinical candi­ NIAID-Supported Tuberculosis dates, as are public-private partnership Vaccine Research opportunities to enhance product To answer the above questions, NIAID is development for Category C agents. funding not only investigator-initiated (For more information, please see research, but solicited research on tubercu­ www.niaid.nih.gov/ research/resources losis immunology, pathology, pathogen­ and www.niaid.nih.gov/biodefense/ esis, vaccine development, target antigen research/funding.htm.) NIAID’s identification, diagnostics, development Tuberculosis Research Unit at of improved tools for epidemiological Case Western Reserve University studies, and development of markers of (www.tbresearchunit.org) and NIAID’s

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Stop TB Partnership, 2006, The Global Plan to 1998;396:190] Stop TB, 2006 -2015, www.stoptb.org/glob­ 8. Doherty TM and Andersen P, Vaccines for alplan/assets/documents/GlobalPlanFinal.pdf tuberculosis: novel concepts and recent 25. Schluger NW, The pathogenesis of tuberculo­ progress, Clin Microbiol Rev 2005;18(4):6887­ sis: the first one hundred (and twenty-three) 702. years, Am J Respir Cell Mol Biol 9. Elias D et al., Effect of deworming on human T 2005;32(4):251-6. cell responses to mycobacterial antigens in 26. Sambandamurthy VK et al., Long-term protec­ helminth-exposed individuals before and after tion against tuberculosis following vaccination bacille Calmette-Guérin (BCG) vaccination, with a severely attenuated double lysine and Clin Exp Immunol 2001;123:219-225. pantothenate auxotroph of Mycobacterium 10. Geiter L, Ending neglect: The elimination of tuberculosis, Infect Immun 2005;73(2):1196­ tuberculosis in the United States. Washington, 1203. DC: Committee on the Elimination of 27. Vuola JM et al., Immunogenicity of an inacti­ Tuberculosis in the United States, Division of vated mycobacterial vaccine for the preven­ Health Promotion and Disease Prevention, tion of HIV-associated tuberculosis: a Institute of Medicine 2000. randomized, controlled trial, AIDS 11. Ginsberg AM, A proposed national strategy for 2003;17(16):2351-2355. tuberculosis vaccine development, Clin Infect 28. World Health Organization, 2005, WHO fact Dis 2000;30 (Suppl 3):S233-S242. sheet number 104: Tuberculosis. 12. Hoft DF et al., Mucosal vaccination of humans http://www.who.int/mediacentre/factsheets/fs inhibits delayed type hypersensitivity to puri­ 104/en/index.html. fied protein derivative but induces mycobacte­ 29. World Health Organization, 2005, Global ria-specific interferon-gamma responses, Clin Tuberculosis Control—Surveillance, Planning, Infect Dis 2000;30 (Suppl 3):S217-S222. Financing, 13. Horwitz MA, Recombinant BCG expressing www.who.int/tb/publications/global_report/2 Mycobacterium tuberculosis major extracellu­ 005/pdf/Full.pdf lar proteins, Microbes Infect 2005;7:947-954. 30. World Health Organization, 2006, Bacille 14. Izzo A et al., NIH pre-clinical screening pro­ Calmette Guérin—Reported estimates of BCG gram: overview and current status, coverage: www.who.int/immunization_moni­ Tuberculosis (Edinb) 2005;85(1-2):25-28.

TUBERCULOSIS 117 118 THE JORDAN REPORT 2007 Varicella-Zoster Virus

Background declined significantly since the introduc­ immunocompromised children reduces tion of the vaccine [6]. disease severity [9]. In children receiving rimary infection with varicella- the live attenuated Oka vaccine, the inci­ zoster virus (VZV) is manifested Zoster dence and severity of breakthrough P as chickenpox (varicella) and Zoster typically involves large areas of infection are inversely correlated with results in a lifelong latent infection. skin that ulcerate and require several antibody titer to VZV glycoproteins, and Reactivation of the latent virus leads to weeks to heal. The skin eruption itself is possibly with the level of T-cell responses shingles (zoster). very painful, and it is often followed by as well [10, 11]. Conversely, it is clear postherpetic neuralgia (PHN), a pain that cellular responses play the primary Varicella syndrome that may persist for many role in preventing disease associated Prior to the introduction of the live months or years and that can be very with reactivation of latent VZV. While attenuated vaccine, approximately 4 mil­ disabling. There is no established therapy decreases in humoral immunity are not lion cases of varicella occurred annually, for PHN. The incidence and severity of associated with increased risk of zoster, primarily in young children, with more zoster and its complications increase with the age-related decline in cell-mediated than 90 percent of the U.S. population age. The incidence among people aged responses to VZV antigens is propor­ becoming seropositive [1]. Chickenpox 50–59 appears to be between two and tional to the age-related increase in the was estimated to cost about $400 million four cases per 1,000 persons per year, and incidence and severity of zoster [12, 13, each year, much of this representing the it more than doubles by the age of 80 14, 15], suggesting that this loss is a cost to parents of lost income from work years. More than one-half of all cases causative factor. [2]. With increasing vaccine coverage, occur in persons 60 years of age and The role of viral immune evasion varicella disease has declined dramatically older [7]. PHN is the major complication mechanisms in VZV infection is not in areas subject to surveillance [3]. As of zoster in the immunocompetent host. well defined. For example, VZV is similar the use of the vaccine expands, it will Rare in individuals less than 40 years of to herpesviruses (HSV) in that its glyco­ lead to changes in the epidemiology and age, PHN is estimated to occur in 25 to protein gE forms a complex with gI and costs of this childhood illness in the more than 50 percent of patients with can act as an Fc receptor, but it is not United States. zoster who are more than 59 years of known whether the similarity to HSV Varicella can be complicated by a age [8]. extends to providing protection from variety of serious conditions, including virus-specific antibody [16]. Efforts are skin infections that can progress to sys­ Current Status and Key Issues currently under way to identify VZV temic infections, infections of the brain, in Research and Development genes that may be associated with evasion and pneumonia [4]. Prior to introduction Humoral and cellular immune of major histocompatibility complex of the vaccine, complications of varicella responses are elicited early in primary (MHC) class I- and class II-mediated were responsible for as many as 9,300 VZV infections, and their relative con­ immune responses [17]. hospitalizations and 100 deaths annually. tribution to protection from disease is Oka, a live attenuated varicella vac­ The risk of these complications is highest not well understood. The impact of cine, was developed in Japan in the early in adults. While less than 5 percent of active humoral immunity appears to be 1970s [18]. In the United States, this varicella cases occur in adults more than limited, but preexisting antibody has vaccine (Varivax) is produced by Merck. 20 years of age, 55 percent of the deaths been shown to provide some level of It was licensed for use in healthy individ­ occur in this age group [5]. As would be protection. Passively acquired maternal uals by the U.S. Food and Drug expected, the number of hospitalizations antibody affords some protection to Administration (FDA) in 1995 and is due to the complications of varicella has infants, and postexposure administration now recommended for universal use in of VZV immunoglobulin (VZIG) to early childhood by the Centers for

VARICELLA-ZOSTER VIRUS 119 Disease Control and Prevention (CDC) In addition to further studies on the Next Steps and Challenges Advisory Committee for Immunization live attenuated virus, there are continuing Ahead Practices, the American Academy of efforts to evaluate alternate vaccines. Although the current varicella vaccine is Pediatrics, and the American Academy of Inactivated virus showed some efficacy highly effective in preventing disease, Family Physicians [19, 20]. The use of in protecting bone marrow transplant outbreaks of varicella are still occasionally Varivax in the United States has been recipients from shingles, although this reported. Furthermore, the dynamics of increasing steadily: in 2004 coverage strategy also has been associated with a protection are likely to change as the among children 19 to 35 months of age weaker MHC class I-restricted cytotoxic incidence of varicella declines further, was estimated at 87.5 percent [21]. All response and reduced protection from and vaccinated children receive less of a states ordered the vaccine for use in varicella when compared to the live boosting effect through natural exposure. their immunization programs, and by attenuated vaccine [28, 29, 30]. Other It has been demonstrated that a second June 2004, a total of 44 states had imple­ strategies being pursued include disabled dose of the varicella vaccine can signifi­ mented elementary school or child care virus and plasmid DNA. cantly decrease the rate of varicella entry requirements for varicella vaccina­ breakthrough illness and increase vaccine tion. Post-licensure surveillance in day- Recent Accomplishments efficacy, and some authorities now feel care centers indicates that the The availability of a live attenuated VZV that a two-dose regimen should be rec­ vaccine is generally well tolerated, leads vaccine that is safe, effective, and FDA- ommended for this age group, as it is for to a lower attack rate, and protects from licensed for the prevention of varicella adolescents and adults [24]. severe disease [22, 23]. However, there presented an opportunity to determine The development of a VZV vaccine remain instances of breakthrough infec­ whether the same vaccination strategy containing virus incapable of becoming tion, and evidence has accumulated that might be effective for preventing zoster reactivated, or of a subunit vaccine, will a single dose of varicella vaccine is not in the elderly. In a collaboration between require much more basic research. sufficiently immunogenic when given to the Veteran’s Administration, the National Studies of the antigenic components some children from 1 to 12 years of age Institute of Allergy and Infectious Diseases most important for developing an [24]. Vaccine-induced immunity appears (NIAID), and Merck & Co., Inc., a Phase immune response in humans, and of to be durable. Studies of individuals III clinical trial was conducted to assess novel methods for presenting viral anti­ immunized up to 20 years previously whether administration of a higher-titer gens to cells of the immune system, are show persistence of antibodies and pro­ version of the varicella vaccine in adults in progress. Other populations at risk tection against serious disease [25, 26, 60 years of age and older can reduce the for severe VZV disease—e.g., pediatric 27]. Further studies will establish incidence and/or severity of zoster and renal transplant recipients—are also can­ whether immunization will provide pro­ its complications. The Shingles Prevention didates for studies evaluating the safety tection as durable as that from natural Study was conducted over five years at and efficacy of the live attenuated vac­ infection, or whether boosting will be 22 study sites across the United States cine. required to maintain protection through and enrolled a total of 38,546 volunteers. adulthood. The expanding use of this The study was completed late in 2004 vaccine will undoubtedly alter the epi­ [31]. Use of the vaccine reduced the demiology and costs of varicella in the burden of illness due to zoster by 61.1 United States, and it affords the oppor­ percent, reduced the incidence of post- tunity to study in greater detail the herpetic neuralgia by 66.5 percent, and correlates of protection against infection reduced the incidence of zoster by 51.3 and disease, and the viral functions percent. The vaccine was also found to associated with virulence and attenuation. be safe and well-tolerated. Based on the It remains to be demonstrated results of this study, licensure was whether the VZV vaccine will be effective approved by the FDA in May 2006. in other populations, such as immuno­ suppressed transplant patients.

120 THE JORDAN REPORT 2007 References 18. Takahashi M et al., Live vaccine used to pre­ 1. Weller TH, Varicella-herpes zoster virus. In AS vent the spread of varicella in children in hos­ Evans and RA Kaslow (Eds.), Viral infections pital, Lancet 1974;2:1288-1290. of humans: Epidemiology and control 19. Centers for Disease Control and Prevention, 1997:865-892. Prevention of varicella: Recommendations of 2. Lieu TA et al., Cost-effectiveness of a routine the Advisory Committee on Immunization varicella vaccination program for U.S. chil­ Practices (ACIP), MMWR Recomm Rep dren, JAMA 1994;271:375-381. 1996;45(RR-11):1-36. 3. Seward JF et al., Varicella disease after intro­ 20. American Academy of Pediatrics, duction of varicella vaccine in the United Recommendations for the use of live attenu­ States, 1995-2000, JAMA 2002;287:606-611. ated varicella vaccine, Pediatrics 1995;95:791­ 4. Arvin AM, Varicella-zoster virus. In BN Fields, 796. DM Knipe, and PM Howley (Eds.), Fields 21. Centers for Disease Control and Prevention, virology 1996;3:2547-2585. National, State, and Urban Area Vaccination 5. Centers for Disease Control and Prevention, Coverage Among Children Aged 19–35 Varicella-related deaths among adults— Months—United States, 2004, MMWR Morb United States, 1997, MMWR Morb Mortal Mortal Wkly Rep 2005;54(29):717-721. Wkly Rep 1997;46:409-412. 22. Izurieta H et al., Postlicensure effectiveness of 6. Davis MD et al., Decline in varicella-related varicella vaccine during an outbreak in a child hospitalizations and expenditures for children care center, JAMA 1997;278:1495-1499. and adults after introduction of varicella vac­ 23. Buchholz U et al., Varicella outbreaks after cine in the United States, Pediatrics vaccine licensure: Should they make you 2004;114:786-792 chicken? Pediatrics 1999;104:561-563. 7. Hope-Simpson RE, The nature of herpes 24. Arvin A and Gershon A, Control of varicella: zoster: A long-term study and a new hypothe­ Why is a two-dose schedule necessary? Pediatr sis, Proc R Soc Med 1965;58:9-20. Infect Dis J 2006;25:475-476. 8. Ragozzino MW et al., Population-based study 25. Ampofo K et al., Persistence of immunity to of herpes zoster and its sequelae, Medicine live attenuated varicella vaccine in healthy (Baltimore) 1982;61:310-316. adults, Clin Infect Dis 2002;34:774-779. 9. Brunell PA et al., Prevention of varicella by 26. Vessey SJR et al., Childhood vaccination zoster immune globulin, N Engl J Med against varicella: Persistence of antibody, 1969;280:1191-1194. duration of protection, and vaccine efficacy, J 10. White CJ et al., Modified cases of chickenpox Pediatr 2001;139:297-304. after varicella vaccination: Correlation of pro­ 27. Steinberg SP et al., Persistence of immunity to tection with antibody response, Pediatr Infect Varicella-Zoster Virus A after vaccination of Dis J 1992;11:19-23. healthcare workers, Infect Control Hosp 11. Bergen RE et al., The immunogenicity of the Epidemiol 2001;22:279-283. Oka/Merck varicella vaccine in relation to 28. Hayward AR et al., Varicella zoster virus-spe­ infectious varicella-zoster virus and relative cific cytotoxicity following secondary immu­ viral antigen content, J Infect Dis nization with live or killed vaccine, Viral 1990;162:1049-1054. Immunol 1996;9:241-245. 12. Webster A et al., Titration of IgG antibodies 29. Vans I and Vesikari T, Efficacy of high-titer against varicella zoster virus before bone mar­ live attenuated varicella vaccine in healthy row transplantation is not predictive of future young children, J Infect Dis 1996;174(Suppl zoster, J Med Virol 1989;27:117-119. 3):S330-S334. 13. Arvin AM et al., Cellular and humoral immu­ 30. Redman RL et al., Early reconstitution of nity in the pathogenesis of recurrent herpes immunity and decreased severity of herpes viral infections in patients with lymphoma, J zoster in bone marrow transplant recipients Clin Invest 1980;65:869-878. immunized with inactivated varicella vaccine, 14. Meyers JD et al., Cell-mediated immunity to J Infect Dis 1997;176:578-585. varicella-zoster virus after allogeneic marrow 31. Oxman MN et al., A vaccine to prevent herpes transplant, J Infect Dis 1980;141:479-487. zoster and postherpetic neuralgia in older 15. Ruckdeschel JC et al., Herpes zoster and adults, N Engl J Med 2005;352:2271-2284. impaired cell-associated immunity to the vari­ cella-zoster virus in patients with Hodgkin’s disease, Am J Med 1977;62:77-85. 16. Nagashunmugam T et al., In vivo immune evasion mediated by the herpes simplex virus type 1 immunoglobulin G Fc receptor, J Virol 1998; 2:5351-5359. 17. Abendroth A and Arvin A, Varicella-zoster virus immune evasion, Immunol Rev 1999;168:143-156.

VARICELLA-ZOSTER VIRUS 121 122 THE JORDAN REPORT 2007 West Nile Virus

he identification of West Nile virus (WNV) in New York in the T summer of 1999 was the first time the mosquito-borne microbe had been detected in the Western Hemisphere. Until then, the virus had been found chiefly in Africa, Eastern Europe, the Middle East, and Asia. Since 1999, WNV has been reported in an ever-growing area, and human cases have been reported from coast to coast in the United States, as well as in Canada and Mexico. Between 1999 and 2005, WNV caused 19,602 cases of the disease in the United States, including 785 deaths, according to the Centers for Disease Control and

Prevention. Applying mosquito repellent to the skin helps prevent mosquitos from biting, thereby, Although infection with WNV usually preventing many arboviral infections, such as West Nile virus. Courtesy of CDC / James Gathany causes only mild symptoms in humans, it can spread to the central nervous system and cause encephalitis, a potentially deadly tics in common. These similarities have protection that candidate WNV and brain inflammation, most common allowed scientists to build on earlier dis­ other licensed flavivirus vaccines might among the elderly. Currently, no treat­ coveries about other flaviviruses that are have against WNV. Researchers found ment is available for WNV encephalitis, closely related to WNV, including that hamsters were completely protected and no licensed vaccine exists to prevent Japanese encephalitis virus, St. Louis by prototype WNV vaccines, and sur­ the human form of the disease. Mosquito encephalitis virus, yellow fever virus, prisingly, at least partially protected by control has been the only available strategy and dengue virus. Japanese encephalitis and yellow fever to combat the rapid spread of this There has been great success control­ vaccines. Thus, these new models are an emerging disease, but effective spraying ling yellow fever and Japanese encephalitis important resource that could be used is difficult to carry out in urban areas. with well-organized vaccination campaigns in the development of WNV vaccines to Faced with the potential for a serious centered on an efficacious vaccine. There­ test the efficacy of a new vaccine candi­ WNV epidemic, National Institute of fore, the National Institutes of Health date (or a new antiviral medicine). Allergy and Infectious Diseases (NIAID)­ (NIH) encouraged similar WNV vaccine NIAID is supporting a number of supported researchers began develop­ development programs. vaccine approaches. One of the earliest ment of a vaccine to prevent infection. Importantly, NIAID-supported began in 1999 when NIAID funded a Basic research on newly emerging basic research studies discovered that fast-track project to develop a candidate microbes has enabled rapid progress in hamsters and mice were good models WNV vaccine with Acambis, Inc. The the development of a WNV vaccine. In for West Nile disease. NIH-supported vaccine is constructed using a vaccine addition, WNV vaccine development researchers at the University of Texas licensed for preventing yellow fever as has benefited from the fact that the Medical Branch, Galveston, conducted the backbone. To create the WNV vac­ virus belongs to a group known as fla­ a series of preliminary experiments to cine, researchers substituted the surface viviruses, which have many characteris- learn more precisely the degree of protein of WNV for the deleted yellow

WEST NILE VIRUS 123 fever virus protein using chimeric tech­ NIAID intramural scientists, with WNV/DEN4 candidate vaccine with the nology developed at NIAID in the early early assistance from collaborators from 30-nucleotide deletion has been tested 1990s. This method of creating chimeric the Walter Reed Army Institute of in monkeys with promising results and flavivirus vaccines is also being applied to Research (WRAIR), capitalized on is currently being tested in humans in developing a vaccine for dengue and advances in recombinant DNA tech­ Phase I clinical trials that began in 2005. Japanese encephalitis virus. The Acambis, nolgy and previous research on dengue Meanwhile, NIAID scientists at the Inc., vaccine has undergone successful virus to produce a new candidate WNV Dale and Betty Bumpers Vaccine Research preclinical evaluations in hamsters, mice, vaccine. The NIAID team already had Center have developed a DNA-based monkeys, and horses, and has yielded successfully tested a strategy that used vaccine against WNV in collaboration encouraging results in a recently com­ the new technology to replace key genes with the San Diego-based biotechnology pleted Phase I clinical trial. In December, of different flaviviruses with those of company Vical, Inc. The vaccine is based 2005, the vaccine was moved into Phase II dengue virus type 4 (DEN4). Unlike on an existing codon-modified gene- clinical trial evaluation, making many flaviviruses, DEN4 does not cause based DNA plasmid vaccine platform designed to express WNV proteins. In April 2005, following pre-clinical safety studies and viral challenge studies, the VRC initiated a Phase I clinical trial to evaluate safety, tolerability, and immune responses of this recombinant DNA vaccine in human volunteers. In addition to pursuing replicating chimeric vaccines, researchers have made advances in the development of non-replicating subunit vaccines. Scientists at Hawaii Biotech, Inc., sup­ ported by the National Institute of Neurological Disorders and Stroke, are using genetically engineered viral pro­ teins that cannot cause disease. Two for­ mulations of the vaccine have been tested in the golden hamster animal model, with promising results. At L2

The Ochlerotatus triseriatus mosquito, commonly referred to as the “treehole mosquito,” is a known vector of Diagnostics, LLC, NIAID-supported West Nile virus. Courtesy of CDC / James Gathany researchers have developed a recombi­ nant subunit vaccine found to induce Acambis, Inc., the first company to enter disease in the brain. The resulting atten­ virus-neutralizing antibodies in mice, Phase II testing of a WNV vaccine. The uated virus strains were safe for use in a rabbits, and horses; these antibodies randomised, double-blind, placebo-con­ vaccine but still protective. The NIAID prevent infection in a murine model of trolled trial is being conducted in more team then used this strategy to combine WNV infection. Researchers are now than 200 volunteers in the United States. genes from WNV and DEN4. This developing a manufacturing process for The safety, tolerability, and immuno­ hybrid virus did not infect the brain, but the vaccine, with the goal of producing a genicity of the vaccine at different dose still stimulated a strong immune vaccine suitable for Phase I clinical trials. levels will be evaluated first in healthy response with even a single dose. This young adults and the optimal dose will WNV/DEN4 chimeric virus was further subsequently be tested in healthy elderly attenuated by deleting 30 nucleotides subjects. from its 3’ untranslated region. The

124 THE JORDAN REPORT 2007 APPENDIXES

APPENDIX A: Status of Vaccine Research and Development, 2006

Target Agent Vaccine Basic R&D Preclinical Phase I Phase II Phase III

Ancyclostoma duodenale Recombinant protein + + + Bacillus anthracis Recombinant subunit + + + + Bordetella pertussis B. pertussis surface protein expressed by vector (e.g., Salmonella and Vibrio cholerae) + + PT peptides-CRM conjugates + + Purified adenylate cyclase + + Blastomyces dermatitidis Purified yeast cell proteins (e.g., WI-1) + + Recombinant proteins (e.g., WI-1) + WI-1 DWA + + Live attenuated strain + + Borrelia burgdorferi Recombinant Osp A + + + + +

Osp A-based DNA vaccine + + BCG-expressed Osp A + + Purified Osp B, Osp C + + + Osp C (14 valent) + + + + DbpA + DbpB + Brugia malayi Purified parasite antigens (paramyosin, etc.) + + Calicivirus Norwalk VLP’s in transgenic potato + + + Norwalk VLP’s orally delivered + + Campylobacter jejuni Inactivated whole cell with mutant E. coli labile toxin (mLT) adjuvant, oral vaccine + + + Whole cell (intact) + + + + Chlamydia trachomatis Major outer membrane protein (MOMB) viral vectors + + Purified major outer membrane protein + Polymorphic membrane protein D + Chlamydia-secreted Protease Factor (CPAF) + Clostridium botulinum Toxoid + + + + Recombinant AB vaccine + + + Recombinant heavy chain + + Clostridium difficile Formalin-inactivated toxins A and B + + + Clostridium tetani Recombinant toxin + + Salmonella vector + + + Microencapsulation + + Transcutaneous immunization + + Candida albicans Cell surface oligomannosyl epitope + + Recombinant Als1p surface protein + +

Note: This list outlines publicly available information concerning the status of vaccines in the research and development pipeline and should not be considered inclusive of all ongoing vaccine research and development.

APPENDIX A 127 Target Agent Vaccine Basic R&D Preclinical Phase I Phase II Phase III Candida albicans (continued) Recombinant Als3p surface protein + + Chikungunya virus Live attenuated + + + + Coccidioides immitis Formalin-killed spherules + + + + + Recombinant protein for Ag2, rAg2 (PRAg2) + + Spherule homogenate (27kxg) + + C-ASWS (Ag2) + + Urease (recombinant and cDNA) (rURE) + + Spherule outer wall glycoprotein (SOWgp) + + PMP-1 + + Corynebacterium Recombinant toxin + + diphtheriae Salmonella vector + + + Transcutaneous immunization + + Coxiella burnetii Formalin inactivated + + + + Antigen immunization + DNA vaccine + Cryptococcus Partially purified capsular polysaccharide + + neoformans Glycoconjugate of capsular polysaccharide with tetanus toxoid + + + Cytomegalovirus (CMV) Live attenuated strains (conventional) + + + + Live attenuated strains (engineered) + + + Glycoprotein subunit vaccine + + + + Multiprotein subunit vaccine + Nucleic acid (DNA) vaccines + + Canarypox vectored + + + VEE-vectored + + Peptide + DNA prime + Inactivated boost + Dengue virus Purified rDNA-expressed viral proteins + + Infectious clone + + Yellow fever/dengue chimeric virus + + + + Inactivated whole virus particle + + + VEE replicon vector + Naked DNA + Vaccinia vector (live) + + Vaccinia subunit + + Baculovirus subunit + + Synthetic peptide + +

Micelle/ISCOM + +

Note: This list outlines publicly available information concerning the status of vaccines in the research and development pipeline and should not be considered inclusive of all ongoing vaccine research and development.

128 THE JORDAN REPORT 2007 Target Agent Vaccine Basic R&D Preclinical Phase I Phase II Phase III Dengue virus (continued) Yeast subunit + + Recombinant envelope (baculovirus and drosophila expression systems) + + Live attenuated dengue virus (monovalent) + + + + Live attenuated dengue virus (combined quadrivalent) + + + + Eastern Equine Inactivated whole virus particles + + + + Encephalitis virus VEE virus Replicon Particle + + Recombinant Eastern/Western encephalitis virus chimera + Ebola virus Recombinant protein subunit (various virus and eukaryotic expression and delivery systems) + + VEE virus Replicon Particle + + Kunjin virus Replicon Particle + Plasmid DNA prime /Adenovirus-expressed protein boost + + Plasmid DNA + + Virus-Like Particle + Recombinant subunit expressed in irradiated Brucella abortus + Endotoxin Detoxified lipopolysaccharide from E. coli (Gram-negative sepsis) 0111:B4, Rc (J5) + + Entamoeba histolytica Yeast subunit + + Recombinant galactose-binding protein + + Galactose-binding proteins expressed in Salmonella + + Enterohemorrhagic Nontoxic mutant toxins + + Escherichia coli (EHEC) [Shiga Intimin + + toxin-producing LPS conjugates + + E. coli (STEC)] Intimin expression in plants + + Stx-1 beta-subunit in Vibrio cholerae vector + + Enterotoxigenic Killed cells and beta-subunit of cholera toxin + + + + Escherichia coli (ETEC) Nontoxigenic ETEC derivative, live attenuated + + + + Salmonella and Shigella vectored CFAs + + Subunit synthetic toxoid (ST) and B subunit of heat-labile toxin (LT) + + LTB expressed in potatoes + + + CFA II microencapsulated + + Epstein-Barr virus (EBV) Glycoprotein subunit (gp350) + + + + Vaccinia recombinant virus expressing gp350 + + + Peptide induction of CTL + + +

Note: This list outlines publicly available information concerning the status of vaccines in the research and development pipeline and should not be considered inclusive of all ongoing vaccine research and development.

APPENDIX A 129 Target Agent Vaccine Basic R&D Preclinical Phase I Phase II Phase III Escherichia coli Anti-FimH adhesin + + (urinary tract) Francisella tularensis Live attenuated + + + Group A streptococcus Glycoconjugate Group A polysaccharide with tetanus toxoid + + M protein, multivalent type-specific epitopes + + + M protein conserved epitope expressed in a commensal vector (S. gordonii) + + M protein conserved epitope in combination with M serotype epitopes + + Cysteine protease + + C5a peptidase + + Fibronectin-binding protein Sfb1 + + Streptococcal pyrogenic exotoxins + + Surface protein(s) + + Group B streptococcus Glycoconjugate vaccines of type Ia, lb, II, III, and V polysaccharides linked to carrier proteins + + + + Surface protein(s) + + Haemophilus ducreyi Outer membrane proteins + + Hemolysin/cytotoxin + + Hemoglobin receptor + + Haemophilus influenzae Recombinant protein subunit containing either (nontypeable) P1, P2, or P6 proteins to serve as carriers in conjugate vaccine preparations + + Recombinant protein subunit containing P4 and P6 + + P4 and P6 + + Subunit Hi nontypeable 47 OMP (adjuvanted) + +

Subunit lipoprotein D (nonacylated) + + + Subunit detoxified lipooligosaccharide conjugate to tetanus toxoid + + Subunit detoxified lipooligosaccharide conjugated to HMW protein from H. influenzae (nontypeable) + + OMP HiN47 + + + + Pili (HifE) + + Haemophilus influenzae Glycoconjugate of Hib PRP with CRM197 + + + + + type b (Hib) Glycoconjugate of Hib PRP with diphtheria toxoid + + + + + Glycoconjugate of Hib PRP with tetanus toxoid + + + + + Hib-IPV-HBV + + + + + Glycoconjugate of Hib PRP with meningococcal type B outer membrane protein + + + + + Glyconjugate Hib with meningococcal type A and/or C + + + Hantaan virus Vaccinia vector + + + +

Note: This list outlines publicly available information concerning the status of vaccines in the research and development pipeline and should not be considered inclusive of all ongoing vaccine research and development.

130 THE JORDAN REPORT 2007 Target Agent Vaccine Basic R&D Preclinical Phase I Phase II Phase III Hantaan virus (continued) Recombinant subunit + RNA replicons + + Non-replicating adenovirus vector + Naked DNA + Helicobacter pylori Recombinant H. pylori urease and cholera toxin-oral vaccine + + + Whole cell vaccine with mutant E. coli heat-labile toxin (LT) adjuvant + + + + H. pylori antigens and mutant CT or LT + + + Killed whole cells + + Salmonella vectored H. pylori antigens + + Multi-epitope DNA vaccine + Hepatitis A virus (HAV) Inactivated HAV particles + + + + + Live attenuated HAV + + + + + Virosome-formulated inactivated HAV + + + + + Viral proteins expressed by vectors + + (baculovirus or vaccinia virus) Hepatitis B virus (HBV) HBV core protein expressed by rDNA + + HBV proteins expressed in yeast cells by rDNA + + + + + Salmonella vector + + + Variants + + Generation of cytotoxic T lymphocytes + + + + DNA vaccines + + rDNA, plants + + + Combined HAV/HBV vaccine Combined inactivated components + + + + + Hepatitis C virus (HCV) rDNA-expressed surface proteins and epitopes + + + + Generation of cytotoxic T lymphocytes + + Nucleocapsid + + DNA vaccines + + Core Ag + immunostimulatory complex + + + + MVA-based rVac w/3 NS protein genes + + Recombinant viruses carrying HCV non- structural genes: adenovirus + + Recombinant viruses carrying various HCV genes: vesicular stomatitis virus (VSV); adeno-associated virus (AAV); Measles virus (MV); Equine herpesvirus (EHV-1); WHV cores + Bacterial recombinants with HCV proteins: Listeria monocytogenes + Cell based vaccines; yeast + Plants systems for HCV protein expression +

Note: This list outlines publicly available information concerning the status of vaccines in the research and development pipeline and should not be considered inclusive of all ongoing vaccine research and development.

APPENDIX A 131 Target Agent Vaccine Basic R&D Preclinical Phase I Phase II Phase III Hepatitis C virus (HCV) Human dendritic cells (matured in vitro with HCV (continued) peptides), for autologous transfer + Hepatitis D virus (HDV) Synthetic peptides + + Baculovirus + Hepatitis E virus (HEV) Expressed proteins + + + + Herpes simplex virus gD2 recombinant protein + + + + + types 1 and 2 Inactivated virus + + + Histoplasma capsulatum Purified yeast cell proteins (e.g., His-62) + + Recombinant proteins (e.g., His 62, H antigen, hsp-70) + + Human immunodeficiency See DAIDS appendix virus, HIV-1

Human papillomavirus (HPV) Bivalent VLP L1 (HPV-11, HPV-16) + + + + + Quadrivalent recombinant VLP L1 (from HPV-6, HPV-11, HPV-16, and HPV-18) + + + + + Influenza virus Inactivated (interpandemic) + + + + + Inactivated (pandemic) + + + + + Cold-adapted live attenuated (interpandemic) + + + + +

Cold-adapted live attenuated (pandemic) + + + Purified viral HA subunit + + + Liposome-containing viral HA + + + + Purified CTL specific peptides + + + Microencapsulated inactivated vaccine + + + Purified, inactivated viral neuraminidase + + + Baculovirus expressed recombinant HA subunit + + + + Baculovirus expressed nucleoprotein + + + Inactivated viral vaccines with novel adjuvants + + + + M2e vaccines with novel adjuvants + + Cell culture derived influenza vaccine + + + + + DNA Vaccines + + + + Recombinant vector vaccines (i.e., adenoviral vectors, VEE vectors) + + Japanese encephalitis virus Whole, inactivated virus particles, mouse brain derived + + + + + Whole, inactivated virus particles, Vero cell derived + + + + + Infectious clone + + Purified DNA expressed protein + + Live attenuated virus (SA-14-14-2) + + + + + Inactivated SA-14-14-2 plus novel adjuvant + + + + + Vaccinia vector (live) + + + Chimeric live attenuated Yellow Fever/Japanese Encephalitis virus + + + +

Note: This list outlines publicly available information concerning the status of vaccines in the research and development pipeline and should not be considered inclusive of all ongoing vaccine research and development.

132 THE JORDAN REPORT 2007 Target Agent Vaccine Basic R&D Preclinical Phase I Phase II Phase III Junin virus Live attenuated (Candid 1) + + + + (Argentine hemorrhagic fever) Lassa virus Chimeric live reassortant Mopeia/Lassa virus + DNA vaccine + Viral-Like Particles + Recombinant subunit expressed in irradiated Brucella abortus + Legionella pneumophila Attenuated mutant + + Purified bacterial surface protein + + Leishmania major Attenuated or killed whole parasites + + + + + Deletion mutagenized, attenuated parasite + + Recombinant trivalent polypeptide + + + + Leishmania amazonensis Killed whole parasites + + + + Multiple Leishmania spp. Leishmanial surface antigens (gp63, 46 kD, and lipophosphoglycan) + + Listeria monocytogenes cytoLLO/cytoPFO vaccine strains + Marburg virus VEE virus Replicon Particle + Baculovirus-expressed protein subunit + Various virus-vectored vaccines + Virus-Like Particle + Measles virus rDNA HA and fusion proteins + + + ISCOM + + Live attenuated + + + + + High-titer live (multiple strains) + + + + + Poxvirus vector (live) + + + Moraxella catarrhalis High molecular weight, outer membrane proteins CD, E, B1, and LBP for use in conjugate vaccines + + Detoxified LOS conjugated to either tetanus toxoid or high MW proteins from nontypeable H. influenzae + + Subunit derived from type IV pilin protein + Mycobacterium leprae Mycobacterium bovis BCG (Bacillus Calmette Guérin) + BCG + heat killed Mycobacterium leprae (HKML) + BCG + killed Mycobacterium vaccae + Killed Mycobacterium vaccae + Killed Mycobacterium habana + ICRC bacilli, heat killed (Indian Cancer Research Center strain) + Mycobacterium welchii, killed + Secretory proteins of Mycobacterium habana + BCG over-expressing Ag85A,B and MPB51 +

Note: This list outlines publicly available information concerning the status of vaccines in the research and development pipeline and should not be considered inclusive of all ongoing vaccine research and development.

APPENDIX A 133 Target Agent Vaccine Basic R&D Preclinical Phase I Phase II Phase III Mycobacterium leprae Adjuvanted Ag85A, B and C proteins + (continued) DNA subunit vaccine of Mycobacterium leprae 35KDa protein + DNA subunit vaccine of Mycobacterium tuberculosis Ag85B + Mycobacterium leprae complex cellular fractions + Adjuvanted Mycobacterium leprae MLSA and MLCwA + Recombinant, adjuvanted Mycobacterium leprae hsp65-CpG DNA vaccine + Mycobacterium tuberculosis Mycobacterium bovis BCG (Bacillus Calmette Guérin) + BCG homologous and heterologous boosting + + + BCG delivered orally + + Mycobacterium vaccae, heat killed + Recombinant BCG over-expressing Ag85A (rBCG30) + + + Recombinant BCG with endosome escape, overexpressing several key antigens (rBCG-Aeras 403) + + Recombinant BCG with endosome escape (rBCGΔUre:CHly+) + + Recombinant BCG with re-introduced RD1 region (BCG::RD1) + Superoxide dismutase (SOD) diminished BCG + + Live attenuated Mycobacterium tuberculosis strains + + Modified vaccinia virus expressing Mycobacterium tuberculosis Ag85A (MVA-85A) + Ag85B + ESAT6 (Hybrid-1) subunit vaccine in IC3 adjuvant + + Ag85B + TB10.4 (Hybrid-4) subunit vaccine in IC3 adjuvant + Mtb72f 9(Mtb39 + Mtb32) subunit vaccine in adjuvant AS02A and AS01B adjuvant + + Nascent BCG protein associated with heat shock proteins as subunit vaccines + Hsp65 DNA vaccine + + Non-replicating Adenovirus 35 expressing multiple proteins of Mycobacterium tuberculosis + Double stranded RNA capsids encoding Mycobacterium tuberculosis antigens + Various adjuvanted protein antigens of Mycobacterium tuberculosis + Various Mycobacterium tuberculosis antigens as DNA vaccines + Mycoplasma pneumoniae Recombinant membrane-associated proteins + + Purified outer membrane protein + + Inactivated (heat-killed) oral vaccine + + +

Note: This list outlines publicly available information concerning the status of vaccines in the research and development pipeline and should not be considered inclusive of all ongoing vaccine research and development.

134 THE JORDAN REPORT 2007 Target Agent Vaccine Basic R&D Preclinical Phase I Phase II Phase III Neisseria gonorrheae Por (protein I) + + Recombinant Por protein + + Iron-binding protein (BPs) + LPS anti-idiotype + Neisseria meningitidis Glycoconjugate with tetanus toxoid + + (Group A) Group A LOS + Neisseria meningitidis Native outer membrane vesicle (NOMV)-intranasal route + + + (Group B) OMP-dLPS liposome + + Recombinant PorA outer membrane protein in liposomes + + Recombinant factor H binding protein + + Membrane vesicle-based vaccine (containing over- expressed proteins normally expressed in low amounts) + Polysaccharide derivative + Outer membrane vesicles (OMV), high MW proteins, and C polysaccharide + + + + + Hexvalent PorA outer membrane vesicle vaccine + + + + Outer membrane vesicles (deoxycholate extracted) + + + + + Recombinant transferrin binding protein (TBP1 and TBP2) + + Recombinant low MW (NspA) outer membrane protein + + Glycoconjugate modified polysaccharide with recombinant PorB protein + + LOS micelle-based vaccine + Genome-derived Neisserial Antigen (Universal) + Neisseria meningitidis Glycoconjugate with tetanus toxoid + + + + + (Group C) Neisseria meningitides Glycoconjugate A and C with CRM197 + + + + A and C Glycoconjugate A and C with DT + + + Neisseria meningitides Combination glycoconjugate with recombinant PorB + + A, B, and C Neisseria meningitides Glycoconjugate with DT + + + A, B, C, and W-135 Nipah virus Poxvirus vectors expressing F and G glycoproteins + Soluble F and G glycoproteins + Newcastle Disease Virus Recombinant Newcastle Disease virus expressing + + foreign HN protein Norwalk Virus VLPs + + + VLPs in transgenic potatoes + + + VLPs in transgenic tomatoes (lyophilized) + + Onchocerca volvulus Recombinant proteins + + Paracoccidioides brasiliensis Purified yeast cell proteins + +

Note: This list outlines publicly available information concerning the status of vaccines in the research and development pipeline and should not be considered inclusive of all ongoing vaccine research and development.

APPENDIX A 135 Target Agent Vaccine Basic R&D Preclinical Phase I Phase II Phase III Paracoccidioides brasiliensis Recombinant proteins + + (continued) Synthetic peptide or multipeptide construction + + (P10, MAP-10) DNA plasmid with gp43 gene + + Parainfluenza virus Cold-adapted PIV3 attenuated virus + + + + Purified HN and F protein subunit vaccine + + Bovine attenuated PIV3 vaccine + + + + Plasmodium falciparum Circumsporozoite antigen-based peptide or recombinant protein + + + + Circumsporozoite antigen fused to hepatitis B surface antigen viral-like particle (RTS, S) + + + + Circumsporozoite antigen epitopes in viral-like particles + + + + Circumsporozoite antigen expressed in various vectors + + + + Circumsporozoite antigen-based DNA vaccine + + + + Noncircumsporozoite, pre-erythrocytic antigen-based constructs + + + + Merozoite surface protein-1 (MSP-1) based recombinant protein + + + Non-MSP-1 asexual blood stage antigens + + + 25-kD gametocyte antigen recombinant protein (TBV25H) + + + Other sexual stage antigens + + Multivalent viral vector-based combination vaccines incorporating different stage-specific antigens (e.g., NYVAC Pf7) + + + + DNA-based combination vaccines incorporating different stage-specific antigens + + Combination vaccines incorporating different stage-specific antigens (e.g., SPf 66) + + + + + Purified irradiated sporozoites + + Genetically attenuated sporozoite + + Plasmodium vivax Circumsporozoite antigen-based peptide or recombinant protein + + + Asexual erythrocytic antigens + + Poliovirus Reversion-stable attenuated OPV + Live (nonreverting) + + Chimeric virus + + Pseudomonas aeruginosa Purified bacterial proteins, including flagellar Ag, LPS-O, porins, several inactivated bacterial toxins, and high MW polysaccharide antigen and glycoconjugate + + + Inactivated whole bacteria-oral preparation + + + Synthetic peptides + + +

Note: This list outlines publicly available information concerning the status of vaccines in the research and development pipeline and should not be considered inclusive of all ongoing vaccine research and development.

136 THE JORDAN REPORT 2007 Target Agent Vaccine Basic R&D Preclinical Phase I Phase II Phase III Pseudomonas (Burkholderia) Purified bacterial proteins, LPS + cepacia Pythium insidiosum Sonicated hyphal antigens + + Culture filtrate antigens + + Purified proteins (e.g., 28, 30, 32 kD) + + Rabies virus rDNA vaccinia virus recombinant for use in sylvatic rabies (veterinary vaccine) + + + + + Inactivated mammalian brain + + + + + Inactivated cell culture + + + + + Replication-defective adenovirus vector + Live attenuated + Respiratory Syncytial Purified F protein subunit vaccine + + + + virus (RSV) Co-purified F, G, and M vaccine + RSV live attenuated strains + + + + Recombinant Sendai virus expressing RSV G protein + + + Recombinant attenuated parainfluenza virus type 3 expressing RSV F protein + + + Recombinant Sendai virus + + + Ricin Toxin Recombinant inactivated toxin + + + Rickettsia rickettsii Subunit vaccine containing major surface proteins (155 and 120 kD) + + Rift Valley Fever virus Inactivated + + + + Live attenuated virus (MP-12) + + + VEE virus Replicon Particle + Sindbis virus Replicon Particle + Virus-Like Particle + Live attenuated recombinant virus + Rotavirus Attenuated human rotavirus strain 89-12 P1A[8], G1—ROTARIX® (GlaxoSmithKline) + + + + + Salmonella expressing VP4, VP7, or both + + Attenuated bovine/human virus reassortants (G1-WC3; G2-WC3; G3-WC3; GA-WC3; P1A[8]-WC3—ROTATEQ® Merck + + + + + Human nursery strains + + + + Purified rotavirus proteins rDNA-derived virus-like particles (VLPs) + + Vaccina virus recombinant expressing VP4, VP7, or both + + DNA vaccines + + Rubella Virus Live attenuated + + + + + Infectious clone + Synthetic peptide +

Note: This list outlines publicly available information concerning the status of vaccines in the research and development pipeline and should not be considered inclusive of all ongoing vaccine research and development.

APPENDIX A 137 Target Agent Vaccine Basic R&D Preclinical Phase I Phase II Phase III Salmonella typhi Vi carbohydrate + + + + + Live attenuated Ty21a vaccine + + + + + Live attenuated auxotrophic mutants + + + + rPAE-Vi conjugate vaccine + + + + + Ty800 live attenuated strain + + + + Live attenuated CVD908-htrA and CVD 909 + + + + Schistosoma mansoni Purified larval antigens + + Recombinant antigens + + Multiple antigen peptides (MAP) + + DNA vaccines + Schistosoma haematobium Recombinant Sh28 GST (S. haematobium glutathione-S-transferase) + + + Schistosoma japonicum Recombinant larval antigens + + DNA vaccine +

Sendai Virus Recombinant Sendai Virus + + + Sendai virus for gene therapy and vaccination + + Severe Acute Respiratory DNA plasmid expressing S protein + + + Syndrome (SARS Co-V) Inactivated viral vaccines + + + Baculovirus expressed S protein + + CHO cell expressed S protein + + Baculovirus expressed S protein with novel adjuvant, intranasally delivered + + Alphavirus replicon vaccine + + Virus-like particle vaccine + Rhabdovirus (rabies) expressing S protein + + Modified vaccinia Ankara (MVA) expressing S protein + + Adenovirus vector expressing S1 or N + + B- and T-epitope peptide-based vaccine + Shigella dysenteriae Live auxotrophic, attenuated mutants + + + Polysaccharide-protein conjugate + + + + Shigella flexneri E. coli hybrids + + + + Polysaccharide-protein conjugate + + + + Live attenuated oral vaccines + + + + LPS proteosome (intranasal) + + LPS-invasin proteins complex + + Shigella sonnei Live attenuated (WRSS1) oral vaccine + + LPS proteosome (intranasal) + + Polysaccharide-protein conjugate + + + + Nucleoprotein + +

Note: This list outlines publicly available information concerning the status of vaccines in the research and development pipeline and should not be considered inclusive of all ongoing vaccine research and development.

138 THE JORDAN REPORT 2007 Target Agent Vaccine Basic R&D Preclinical Phase I Phase II Phase III Staphylococcus aureus Clumping Factor B + rAls3p-N + Polymeric N-acetylglucosamine + Staphylococcus aureus protein/polypeptide antigen expressed in yeast surface proteins IsdA, IsdB, SdrD, SdrE + Staphylococcal enterotoxin B Recombinant toxin + + Streptococcus pneumoniae Glycoconjugate vaccine (1, 3, 4, 5, 6B, 7F, 9V, 14, 18C, 19F, 23F) conjugated to CRM197 + + + + + 23-valent licensed vaccine with novel adjuvants (Quil A, QS21, MPL) + + + Glycoconjugate multivalent vaccine with novel adjuvants (e.g., MPL) + + + PspA + + + PsaA + + Pneumolysin + + Autolysin + + Neuraminidase + + Glycoconjugate vaccine (1, 3, 4, 5, 6B, 7F, 9V, 14, 18C, 19F, 23F) linked to either tetanus or diphtheria toxoid carrier + + + + + Phospholcholine + + Synthetic peptide epitopes and capsular polysaccharide combined + + Genetic fusions (PspA-IL2 and PspA-GM-CSF) + + CpG motifs cross-linked with 7-valent pneumococcal vaccine + + PGCvax (a fusion protein) + + + Tick-borne Encephalitis virus DNA vaccine + + Inactivated, alum adjuvant + + + + Recombinant subunit vaccine + Chimeric live attenuated dengue/TBE virus + Recombinant Vaccinia virus + Toxoplasma gondii Recombinant parasite surface protein (p30) + + Live attenuated parasites + + Parasite surface protein expressed in viral vector + + Treponema pallidum Membrane proteins + Trypanosoma cruzi Recombinant peptide + + Varicella zoster virus Live, attenuated vaccine + + + + + Subunit, glycoproteins + Vaccinia-vectored glycoprotein +

Note: This list outlines publicly available information concerning the status of vaccines in the research and development pipeline and should not be considered inclusive of all ongoing vaccine research and development.

APPENDIX A 139 Target Agent Vaccine Basic R&D Preclinical Phase I Phase II Phase III Venezuelan Equine Inactivated, whole virus particles + + + + Encephalitis Live attenuated virus strain (TC-83) + + + + Live attenuated mutagenized virus (V3526) + + + Infectious clones + + VEE virus Replicon Particle + + Vibrio cholerae Killed bacteria plus toxin B subunit + + + + + Live recombinant O1 + + + + + Live recombinant O139 + + + + Conjugate lipopolysaccharide (LPS) + + Yellow Fever virus Live attenuated + + + + + Infectious clone + + Western Equine Inactivated, whole virus particles + + + + Encephalitis virus VEE virus Replicon Particle + + West Nile virus Chimeric live attenuated Yellow Fever/ West Nile virus + + + + Chimeric live attenuated dengue/West Nile virus + + + DNA vaccine + + + Drosophila and Baculovirus-expressed recombinant + + protein subunit Yersinia pestis Recombinant subunit + +

Note: This list outlines publicly available information concerning the status of vaccines in the research and development pipeline and should not be considered inclusive of all ongoing vaccine research and development.

140 THE JORDAN REPORT 2007 APPENDIX B: Vaccines Licensed for Immunization and Distribution in the US*

Product Name Trade Name Sponsor Anthrax Vaccine Adsorbed BioThrax BioPort Corp1 BCG Live TICE BCG Organon Teknika Corp BCG Live Mycobax Aventis Pasteur, Ltd2 Diphtheria & Tetanus Toxoids Adsorbed No Trade Name Aventis Pasteur, Inc3 Diphtheria & Tetanus Toxoids Adsorbed No Trade Name Aventis Pasteur, Ltd2 Diphtheria & Tetanus Toxoids & Acellular Pertussis Vaccine Adsorbed Tripedia Aventis Pasteur, Inc3 Diphtheria & Tetanus Toxoids & Acellular Pertussis Vaccine Adsorbed Infanrix GlaxoSmithKline Diphtheria & Tetanus Toxoids & Acellular Pertussis Vaccine Adsorbed DAPTACEL Aventis Pasteur, Ltd Diphtheria & Tetanus Toxoids & Acellular Pertussis Vaccine Adsorbed, Pediarix SmithKline Beecham Hepatitis B (recombinant) and Inactivated Poliovirus Vaccine Combined Biologicals Haemophilus b Conjugate Vaccine (Diphtheria CRM197 Protein Conjugate) HibTITER Lederle Lab Div, American Cyanamid Co Haemophilus b Conjugate Vaccine (Meningococcal Protein Conjugate) PedvaxHIB Merck & Co, Inc Haemophilus b Conjugate Vaccine (Tetanus Toxoid Conjugate) ActHIB Aventis Pasteur, SA4 Haemophilus b Conjugate Vaccine (Meningococcal Protein Conjugate) & Comvax Merck & Co, Inc Hepatitis B Vaccine (Recombinant) Hepatitis A Vaccine, Inactivated Havrix GlaxoSmithKline Hepatitis A Vaccine, Inactivated VAQTA Merck & Co, Inc Hepatitis A Inactivated and Hepatitis B (Recombinant) Vaccine Twinrix GlaxoSmithKline Hepatitis B Vaccine (Recombinant) Recombivax HB Merck & Co, Inc Hepatitis B Vaccine (Recombinant) Engerix-B GlaxoSmithKline Influenza Virus Vaccine FluLaval ID Biomedical Corp of Quebec Influenza Virus Vaccine, Live, Intranasal FluMist MedImmune Vaccines, Inc Influenza Virus Vaccine, Trivalent, Types A and B Fluarix GlaxoSmithKline Biologicals Influenza Virus Vaccine, Trivalent, Types A and B Fluvirin Evans Vaccines5 Influenza Virus Vaccine, Trivalent, Types A and B Fluzone Aventis Pasteur, Inc3 Japanese Encephalitis Virus Vaccine Inactivated JE-Vax Research Foundation for Microbial Diseases of Osaka University Measles Virus Vaccine, Live Attenuvax Merck & Co, Inc Measles and Mumps Virus Vaccine, Live M-M-Vax Merck & Co, Inc (not available) Measles, Mumps, and Rubella Virus Vaccine, Live M-M-R II Merck & Co, Inc Measles, Mumps, Rubella and Varicella Virus Vaccine Live ProQuad Merck & Co, Inc Meningococcal Polysaccharide (Serogroups A, C, Y and W-135) Menactra Aventis Pasteur, Inc Diphtheria Toxoid Conjugate Vaccine

APPENDIX B 141 Product Name Trade Name Sponsor Meningococcal Polysaccharide Vaccine, Groups A, C, Y and W-135 Combined Menomune- Aventis Pasteur, Inc3 A/C/Y/W-135 Mumps Virus Vaccine Live Mumpsvax Merck & Co, Inc Pneumococcal Vaccine, Polyvalent Pneumovax 23 Merck & Co, Inc Pneumococcal 7-valent Conjugate Vaccine (Diphtheria CRM 197 Protein) Prevnar Lederle Lab Div, American Cyanamid Co Poliovirus Vaccine Inactivated (Human Diploid Cell) Poliovax Aventis Pasteur, Ltd2 (not available) Poliovirus Vaccine Inactivated (Monkey Kidney Cell) IPOL Aventis Pasteur, SA4 Quadrivalent Human Papillomavirus (Types 6, 11, 16, 18) Recombinant Vaccine GARDASIL Merck & Co., Inc. Rabies Vaccine Imovax Aventis Pasteur, SA4 Rabies Vaccine RabAvert Chiron Behring GmbH & Co Rabies Vaccine Adsorbed No Trade Name BioPort Corp1 (not available) Rotavirus Vaccine, Live, Oral, Pentavalent RotaTeq Merck & Co., Inc. Rubella Virus Vaccine Live Meruvax II Merck & Co, Inc Smallpox Vaccine, Dried, Calf Lymph Type Dryvax Wyeth Laboratories, Inc (available only thru CDC or DoD programs) Tetanus & Diphtheria Toxoids Adsorbed for Adult Use No Trade Name Massachusetts Public Health Biologic Lab Tetanus & Diphtheria Toxoids Adsorbed for Adult Use DECAVAC Aventis Pasteur, Inc3 Tetanus & Diphtheria Toxoids Adsorbed for Adult Use No Trade Name Aventis Pasteur, Ltd (not available) Tetanus Toxoid No Trade Name Aventis Pasteur, Inc3 Tetanus Toxoid Adsorbed No Trade Name Massachusetts Public Health Biologic Lab Tetanus Toxoid Adsorbed No Trade Name Aventis Pasteur, Inc3 Tetanus Toxoid, Reduced Diphtheria Toxoid and Acellular Pertussis Adacel Aventis Pasteur, Ltd Vaccine, Adsorbed Tetanus Toxoid, Reduced Diphtheria Toxoid and Acellular Pertussis Boostrix GlaxoSmithKline Vaccine, Adsorbed Biologicals Typhoid Vaccine Live Oral Ty21a Vivotif Berna Biotech, Ltd Typhoid Vi Polysaccharide Vaccine TYPHIM Vi Aventis Pasteur, SA4 Varicella Virus Vaccine Live Varivax Merck & Co, Inc Yellow Fever Vaccine YF-Vax Aventis Pasteur, Inc3 Zoster Vaccine, Live, (Oka/Merck) Zostavax Merck & Co., Inc.

*United States Food and Drug Administration, Center for Biologics Evaluation and Research (Information updated 10/11/2006)

142 THE JORDAN REPORT 2007 Footnotes 1. BioPort Corporation acquired product ownership on November 12, 1998 from the Michigan Biologic Products Institute, formerly under the Michigan Department of Public Health. 2. Aventis Pasteur, Ltd obtained product ownership from Connaught Laboratories, Ltd, effective February 24, 2000. 3. Aventis Pasteur, Inc obtained product ownership from Connaught Laboratories, Inc effective December 9, 1999. 4. Aventis Pasteur, SA is the new corporate name for Pasteur Merieux Serums et Vaccins, SA effective February 4, 2000. 5. Powderject obtained product ownership from Evans Medical Ltd. Effective 2001 6. Wyeth Laboratories, Inc is the new corporate name for Wyeth-Ayerst, Inc, effective July 1, 1980.

APPENDIX B 143 144 THE JORDAN REPORT 2007 APPENDIX C: HIV VACCINE CANDIDATES IN PRECLINICAL DEVELOPMENT January 2007

Vaccine * HIV Subtype Preclinical Partners** Manufacture MVA C UCT, SAAVI, Therion Therion DNA C UCT, SAAVI Althea DNAs + IL-12 or IL-15 DNA B U. Penn (D. Weiner), Wyeth Althea Multiepitope DNA + MVA Multi-epitope Pharmexa Epimmune Althea/Barvarian-Nordic VEE replicons C Alphavax Alphavax Novel Adenoviral Vectors A Harvard (D. Barouch) Crucell Novel Adenoviral Vectors A VRC GenVec VSV vector B Wyeth Vaccines Henagen Env protein C Chiron Chiron AAV-based vectors A Children’s Hospital of Philadelphia, Targeted Genetics Targeted Genetics

APPENDIX C 145 146 THE JORDAN REPORT 2007 APPENDIX D APPENDIX D: CLINICAL TRIALS OF HIV VACCINE CANDIDATES IN HIV-UNINFECTED ADULTS February 16, 2007

Protocol Type of Vaccine/Antigens HIV Clade Adjuvant and/or Developer Manufacturer Conducting Phase Vaccine Formulation Trial

DNA

— DNA DNA plasmid BC — — — Guangxi CDC Phase I China

C060301 DNA GTU®MultiHIV B clade, DNA plasmid. expressing B — FIT Biotech, IAVI FIT Biotech FIT Biotech Phase I Finland nef, rev, tat, gag, pol, env, and CTL epitopes

HVTN 060 DNA Gag DNA B IL-12 DNA Wyeth Wyeth NIAID/HVTN Phase I United States, Thailand

HVTN 063 DNA Gag DNA B IL-12 DNA Wyeth Wyeth NIAID/HVTN Phase I IL-15 DNA United States

DNA plus Peptide

HVTN 064 DNA EP HIV-1090 DNA vaccine, expressing 21 CTL Conserved across Polyvinylpyrrolid Pharmexa- Pharmexa- NIAID/HVTN Phase I epitopes from gag, pol, env, nef, rev, vpr, and the multiple clades one (PVP, Plasdone® Epimmune Epimmune United States universal HTL epitope PADRE® povidone)

Peptide EP-1043: gag, pol, and vpu peptides Aluminum hydroxide (Alhydrogel®)

DNA plus Protein

HVTN 049 DNA Env DNA and gag DNA vaccines as PLG microparticles B polylactide coglycolide Chiron/Novartis Chiron/Novartis NIAID/HVTN Phase I (PLG). microparticles Unikted States

Protein gp140 (oligomeric, V2-deleted) B MF-59

DNA plus Live Vector: Modified Vaccinia Ankara (MVA)

HVTN 065 DNA pGA2/JS7: Env, gag, protease, reverse transcriptase, B — GeoVax Strathmann Biotech NIAID/HVTN Phase I Rev, Tat, and Vpu Quiagen Untied States

Live vector MVA62(2), expressing gag, pol, env B — BioReliance Ltd

HIVIS 02 Live vector MVA-CMDR, MVA expressing HIV-1 CRF01A_E AE — WRAIR NIAID, WRAIR Karolinska Phase I Sweden Institute

DNA gp160, and rev DNA vaccines and p17/p24, A, B, C; B +/- sargramostim Swedish Institute Karolinska Institute, and rt DNA vaccines A and B; B (rGM-CSF) for Infectious SMI, Vecura — Disease Control (SMI) 147

I

anzania, Uganda Phase I Phase United States Phase Ib United States Phase II Kenya, Phase I T United States Phase II Phase I United States, Brazil, Haiti, Jamaica, S. Africa Uganda Phase I Kenya, Rwanda Phase United States

s

VI, NIAID/HVTN rial NIAID/HVTN Conducting T NIAID/HVTN NIAID VRC WRAIR, NIAID VRC NIAID/HVTN WRAIR, NIAID VRC IA St. Jude Children’ Research Hospital

s

ical ical ical ical ical ical ical V Manufactur er Molecular Medicine, Genvec Inc V Molecular Medicine, Genvec Inc Molecular Medicine, Genvec Inc V V Molecular Medicine, Genvec Inc V Molecular Medicine, Genvec Inc V Molecular Medicine, Genvec Inc V Molecular Medicine, Genvec Inc St. Jude Children’ Research Hospital

s

Developer NIAID VRC NIAID VRC NIAID VRC NIAID VRC NIAID VRC NIAID VRC NIAID VRC St. Jude Children’ Research Hospital

Adjuvant and/or For mulation — — — — — — — — — — — ------— —

A, B, C A, B, C A, B, C A, B, C HIV Clade A, B, C A, B, C A, B, C A, B, C A, B, C A, B, C A, B, C A, B, C A, B, C B

ADV014-00-VP: adenoviral vectors ADV014-00-VP: adenoviral vectors ADV014-00-VP: adenoviral vectors ADV014-00-VP: adenoviral vectors ADV014-00-VP: adenoviral vectors

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148 THE JORDAN REPORT 2007

States; Puerto States, Puerto Phase I India Phase I United States Phase I Phase IIb United Rico, Canada, Dominican Republic, Haiti, Jamaica, Brazil, Per u, Australia Phase II South Phase I United States United States Phase I United Phase I United Rico, Peru, Haiti, South Africa, Malawi, Dominican Republic, Brazil, Thailand Africa, Uganda, Zambia Phase I China States, Brazil Phase

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APPENDIX D 149 France

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150 THE JORDAN REPORT 2007 APPENDIX E

Recommended Immunization Schedules for Persons Aged 0–18 Years — United States, 2007

Weekly January 5, 2007 / Vol. 55 / Nos. 51 & 52 QuickGuide

The Advisory Committee on Immunization Practices • The main change to the format of the schedule is the (ACIP) periodically reviews the recommended immunization division of the recommendation into two schedules: one schedule for persons aged 0–18 years to ensure that the sched­ schedule for persons aged 0–6 years (Figure 1) and ule is current with changes in vaccine formulations and another for persons aged 7–18 years (Figure 2). Special reflects revised recommendations for the use of licensed vac­ populations are represented with purple bars; the cines, including those newly licensed. 11–12 years assessment is emphasized with the bold, capi­ The changes to the previous childhood and adolescent talized fonts in the title of that column. Rota, HPV, and immunization schedule, published January 2006 (1), are as varicella vaccines are incorporated in the catch-up follows: immunization schedule (Table). • The new rotavirus vaccine (Rota) is recommended in a 3-dose schedule at ages 2, 4, and 6 months. The first dose Vaccine Information Statements should be administered at ages 6 weeks through 12 weeks The National Childhood Vaccine Injury Act requires that with subsequent doses administered at 4–10 week inter­ health-care providers provide parents or patients with copies vals. Rotavirus vaccination should not be initiated for of Vaccine Information Statements before administering each infants aged >12 weeks and should not be administered dose of the vaccines listed in the schedule. Additional infor­ after age 32 weeks (2). mation is available from state health departments and from • The influenza vaccine is now recommended for all chil­ CDC at http://www.cdc.gov/nip/publications/vis. dren aged 6–59 months (3). Detailed recommendations for using vaccines are available from package inserts, ACIP statements on specific vaccines, • Varicella vaccine recommendations are updated. The first and the 2003 Red Book (6). ACIP statements for each recom­ dose should be administered at age 12–15 months, and a mended childhood vaccine are available from CDC at newly recommended second dose should be administered http://www.cdc.gov/nip/publications/acip-list.htm. In at age 4–6 years (4). addition, guidance for obtaining and completing a Vaccine • The new human papillomavirus vaccine (HPV) is rec­ Adverse Event Reporting System form is available at http:// ommended in a 3-dose schedule with the second and third www.vaers.hhs.gov or by telephone, 800-822-7967. doses administered 2 and 6 months after the first dose. References Routine vaccination with HPV is recommended for 1. CDC. Recommended childhood and adolescent immunization females aged 11–12 years; the vaccination series can be schedule—United States. MMWR 2006;54(52):Q1–Q4. started in females as young as age 9 years; and a catch-up 2. CDC. Prevention of rotavirus gastroenteritis among infants and vaccination is recommended for females aged 13–26 years children. Recommendations of the Advisory Committee on Immuniza­ tion Practices (ACIP). MMWR 2006;55(No. RR-12):1–13. who have not been vaccinated previously or who have 3.CDC. Prevention and control of influenza. Recommendations of the not completed the full vaccine series (5). Advisory Committee on Immunization Practices (ACIP). MMWR 2006;55(No. RR-10):1–42. 4.CDC. ACIP provisional recommendations for the prevention of varicella. Available at http://www.cdc.gov/nip/vaccine/varicella/varicella_ The recommended immunization schedules for persons aged 0–18 years and the catch­ acip_recs_prov_june_2006.pdf. up immunization schedule for 2007 have been approved by the Advisory Committee 5.CDC. ACIP provisional recommendations for the use of quadrivalent on Immunization Practices, the American Academy of Pediatrics, and the American Academy of Family Physicians. The standard MMWR footnote format has been modified HPV vaccine. Available at http://www.cdc.gov/nip/recs/provisional_ for publication of this schedule. recs/hpv.pdf. 6. American Academy of Pediatrics. Active and passive immunization. In: Suggested citation: Centers for Disease Control and Prevention. Recommended immunization schedules for persons aged 0–18 years—United States, 2007. MMWR Pickering LK, ed. 2003 red book: report of the Committee on Infec­ 2006;55(51&52):Q1–Q4. tious Diseases. 26th ed. Elk Grove Village, IL: American Academy of Pediatrics; 2003.

APPENDIX E 151 Q-2 MMWR QuickGuide January 5, 2007

FIGURE 1. Recommended immunization schedule for persons aged 0–6 years — United States, 2007

Age 1 2 4 6 12 15 18 19–23 2–3 4–6 Vaccine Birth month months months months months months months months years years 1 See Hepatitis B HepB HepB footnote 1 HepB HepB Series Rotavirus2 Rota Rota Rota Range of Diphtheria, 3 DTaP DTaP DTaP DTaP DTaP recommended Tetanus, Pertussis Haemophilus ages Hib 4 influenzae type b4 Hib Hib Hib Hib

5 PCV Pneumococcal PCV PCV PCV PCV PPV Inactivated IPV IPV IPV IPV Catch-up Poliovirus immunization Influenza6 Influenza (Yearly) Measles, Mumps, 7 MMR MMR Rubella Varicella8 Varicella Varicella 9 Certain Hepatitis A HepA (2 doses) HepA Series high-risk Meningococcal10 MPSV4 groups

This schedule indicates the recommended ages for routine administration of currently of the vaccine are not contraindicated and if approved by the Food and Drug licensed childhood vaccines, as of December 1, 2006, for children aged 0–6 years. Administration for that dose of the series. Providers should consult the respective Additional information is available at http://www.cdc.gov/nip/recs/child-schedule.htm. Advisory Committee on Immunization Practices statement for detailed Any dose not administered at the recommended age should be administered at any recommendations. Clinically significant adverse events that follow immunization should subsequent visit, when indicated and feasible. Additional vaccines may be licensed be reported to the Vaccine Adverse Event Reporting System (VAERS). Guidance and recommended during the year. Licensed combination vaccines may be used about how to obtain and complete a VAERS form is available at http://www.vaers. whenever any components of the combination are indicated and other components hhs.gov or by telephone, 800-822-7967.

1. Hepatitis B vaccine (HepB). (Minimum age: birth) 5. Pneumococcal vaccine. (Minimum age: 6 weeks for pneumococcal conjugate At birth: vaccine [PCV]; 2 years for pneumococcal polysaccharide vaccine [PPV]) •Administer monovalent HepB to all newborns before hospital discharge. • Administer PCV at ages 24–59 months in certain high-risk groups. Administer • If mother is hepatitis surface antigen (HBsAg)-positive, administer HepB and PPV to children aged >2 years in certain high-risk groups. See MMWR 0.5 mL of hepatitis B immune globulin (HBIG) within 12 hours of birth. 2000;49(No. RR-9):1–35. • If mother’s HBsAg status is unknown, administer HepB within 12 hours of birth. 6. Influenza vaccine. (Minimum age: 6 months for trivalent inactivated influenza Determine the HBsAg status as soon as possible and if HBsAg-positive, vaccine [TIV]; 5 years for live, attenuated influenza vaccine [LAIV]) administer HBIG (no later than age 1 week). • All children aged 6–59 months and close contacts of all children aged • If mother is HBsAg-negative, the birth dose can only be delayed with physician’s 0–59 months are recommended to receive influenza vaccine. order and mothers’ negative HBsAg laboratory report documented in the infant’s •Influenza vaccine is recommended annually for children aged >59 months with medical record. certain risk factors, health-care workers, and other persons (including household After the birth dose: members) in close contact with persons in groups at high risk. See MMWR • The HepB series should be completed with either monovalent HepB or a 2006;55(No. RR-10):1–41. combination vaccine containing HepB. The second dose should be administered • For healthy persons aged 5–49 years, LAIV may be used as an alternative to TIV. at age 1–2 months. The final dose should be administered at age >24 weeks. •Children receiving TIV should receive 0.25 mL if aged 6–35 months or 0.5 mL if Infants born to HBsAg-positive mothers should be tested for HBsAg and antibody aged >3 years. to HBsAg after completion of >3 doses of a licensed HepB series, at age •Children aged <9 years who are receiving influenza vaccine for the first time 9–18 months (generally at the next well-child visit). should receive 2 doses (separated by >4 weeks for TIV and >6 weeks for LAIV). 4-month dose: 7. Measles, mumps, and rubella vaccine (MMR). (Minimum age: 12 months) • It is permissible to administer 4 doses of HepB when combination vaccines are •Administer the second dose of MMR at age 4–6 years. MMR may be administered administered after the birth dose. If monovalent HepB is used for doses after before age 4–6 years, provided >4 weeks have elapsed since the first dose and the birth dose, a dose at age 4 months is not needed. both doses are administered at age >12 months. 2. Rotavirus vaccine (Rota). (Minimum age: 6 weeks) 8. Varicella vaccine. (Minimum age: 12 months) •Administer the first dose at age 6–12 weeks. Do not start the series later than •Administer the second dose of varicella vaccine at age 4–6 years. Varicella age 12 weeks. vaccine may be administered before age 4–6 years, provided that >3 months • Administer the final dose in the series by age 32 weeks. Do not administer a have elapsed since the first dose and both doses are administered at age dose later than age 32 weeks. >12 months. If second dose was administered >28 days following the first dose, • Data on safety and efficacy outside of these age ranges are insufficient. the second dose does not need to be repeated. 3. Diphtheria and tetanus toxoids and acellular pertussis vaccine (DTaP). 9.Hepatitis A vaccine (HepA). (Minimum age: 12 months) (Minimum age: 6 weeks) •HepA is recommended for all children aged 1 year (i.e., aged 12–23 months). •The fourth dose of DTaP may be administered as early as age 12 months, The 2 doses in the series should be administered at least 6 months apart. provided 6 months have elapsed since the third dose. •Children not fully vaccinated by age 2 years can be vaccinated at subsequent visits. •Administer the final dose in the series at age 4–6 years. • HepA is recommended for certain other groups of children, including in areas where 4. Haemophilus influenzae type b conjugate vaccine (Hib). (Minimum age: 6 weeks) vaccination programs target older children. See MMWR 2006;55(No. RR-7):1–23. • If PRP-OMP (PedvaxHIB® or ComVax® [Merck]) is administered at ages 2 and 10. Meningococcal polysaccharide vaccine (MPSV4). (Minimum age: 2 years) 4 months, a dose at age 6 months is not required. •Administer MPSV4 to children aged 2–10 years with terminal complement •TriHiBit® (DTaP/Hib) combination products should not be used for primary deficiencies or anatomic or functional asplenia and certain other high-risk groups. immunization but can be used as boosters following any Hib vaccine in children See MMWR 2005;54(No. RR-7):1–21. aged >12 months.

The Recommended Immunization Schedules for Persons Aged 0–18 Years are approved by the Advisory Committee on Immunization Practices (http://www.cdc.gov/nip/acip), the American Academy of Pediatrics (http://www.aap.org), and the American Academy of Family Physicians (http://www.aafp.org).

152 THE JORDAN REPORT 2007 Vol. 55 MMWR QuickGuide Q-3

FIGURE 2. Recommended immunization schedule for persons aged 7–18 years — United States, 2007

Age 7–10 11–12 13–14 15 16–18 Vaccine years YEARS years years years 1 See Tetanus, Diphtheria, Pertussis footnote 1 Tdap Tdap Range of See Human Papillomavirus2 footnote 2 HPV (3 doses) HPV Series recommended MCV43 ages Meningococcal3 MCV4 MPSV4 MCV4 Pneumococcal4 PPV 5 Influenza (Yearly) Influenza Catch-up Hepatitis A6 HepA Series immunization Hepatitis B7 HepB Series Inactivated Poliovirus8 IPV Series Certain 9 MMR Series Measles, Mumps, Rubella high-risk Varicella10 Varicella Series groups

This schedule indicates the recommended ages for routine administration of currently of the vaccine are not contraindicated and if approved by the Food and Drug licensed childhood vaccines, as of December 1, 2006, for children aged 7–18 years. Administration for that dose of the series. Providers should consult the respective Additional information is available at http://www.cdc.gov/nip/recs/child-schedule.htm. Advisory Committee on Immunization Practices statement for detailed Any dose not administered at the recommended age should be administered at any recommendations. Clinically significant adverse events that follow immunization should subsequent visit, when indicated and feasible. Additional vaccines may be licensed be reported to the Vaccine Adverse Event Reporting System (VAERS). Guidance and recommended during the year. Licensed combination vaccines may be used about how to obtain and complete a VAERS form is available at http://www.vaers. whenever any components of the combination are indicated and other components hhs.gov or by telephone, 800-822-7967.

1. Tetanus and diphtheria toxoids and acellular pertussis vaccine (Tdap). 6. Hepatitis A vaccine (HepA). (Minimum age: 12 months) (Minimum age: 10 years for BOOSTRIX ® and 11 years for ADACEL ™ ) •The 2 doses in the series should be administered at least 6 months apart. •Administer at age 11–12 years for those who have completed the recommended • HepA is recommended for certain other groups of children, including in areas childhood DTP/DTaP vaccination series and have not received a tetanus and where vaccination programs target older children. See MMWR 2006;55 diphtheria toxoids vaccine (Td) booster dose. (No. RR-7):1–23. •Adolescents aged 13–18 years who missed the 11–12 year Td/Tdap booster 7. Hepatitis B vaccine (HepB). (Minimum age: birth) dose should also receive a single dose of Tdap if they have completed the •Administer the 3-dose series to those who were not previously vaccinated. recommended childhood DTP/DTaP vaccination series. •A 2-dose series of Recombivax HB® is licensed for children aged 11–15 years. 2. Human papillomavirus vaccine (HPV). (Minimum age: 9 years) 8. Inactivated poliovirus vaccine (IPV). (Minimum age: 6 weeks) •Administer the first dose of the HPV vaccine series to females at age 11–12 years. • For children who received an all-IPV or all-oral poliovirus (OPV) series, a fourth •Administer the second dose 2 months after the first dose and the third dose dose is not necessary if the third dose was administered at age >4 years. 6 months after the first dose. • If both OPV and IPV were administered as part of a series, a total of 4 doses •Administer the HPV vaccine series to females at age 13–18 years if not previously should be administered, regardless of the child’s current age. vaccinated. 9. Measles, mumps, and rubella vaccine (MMR). (Minimum age: 12 months) 3. Meningococcal vaccine. (Minimum age: 11 years for meningococcal conjugate • If not previously vaccinated, administer 2 doses of MMR during any visit, with vaccine [MCV4]; 2 years for meningococcal polysaccharide vaccine [MPSV4]) >4 weeks between the doses. •Administer MCV4 at age 11–12 years and to previously unvaccinated adolescents 10. Varicella vaccine. (Minimum age: 12 months) at high school entry (at approximately age 15 years). •Administer 2 doses of varicella vaccine to persons without evidence of immunity. •Administer MCV4 to previously unvaccinated college freshmen living in • Administer 2 doses of varicella vaccine to persons aged <13 years at least dormitories; MPSV4 is an acceptable alternative. 3 months apart. Do not repeat the second dose, if administered >28 days after •Vaccination against invasive meningococcal disease is recommended for children the first dose. and adolescents aged >2 years with terminal complement deficiencies or • Administer 2 doses of varicella vaccine to persons aged >13 years at least anatomic or functional asplenia and certain other high-risk groups. See MMWR 4 weeks apart. 2005;54(No. RR-7):1–21. Use MPSV4 for children aged 2–10 years and MCV4 or MPSV4 for older children. 4. Pneumococcal polysaccharide vaccine (PPV). (Minimum age: 2 years) •Administer for certain high-risk groups. See MMWR 1997;46(No. RR-8):1–24, and MMWR 2000;49(No. RR-9):1–35. 5. Influenza vaccine. (Minimum age: 6 months for trivalent inactivated influenza vaccine [TIV]; 5 years for live, attenuated influenza vaccine [LAIV]) • Influenza vaccine is recommended annually for persons with certain risk factors, health-care workers, and other persons (including household members) in close contact with persons in groups at high risk. See MMWR 2006;55 (No. RR-10):1–41. •For healthy persons aged 5–49 years, LAIV may be used as an alternative to TIV. •Children aged <9 years who are receiving influenza vaccine for the first time should receive 2 doses (separated by >4 weeks for TIV and >6 weeks for LAIV).

The Recommended Immunization Schedules for Persons Aged 0–18 Years are approved by the Advisory Committee on Immunization Practices (http://www.cdc.gov/nip/acip), the American Academy of Pediatrics (http://www.aap.org), and the American Academy of Family Physicians (http://www.aafp.org). Q-4 MMWR QuickGuide January 5, 2007

TABLE. Catch-up immunization schedule for persons aged 4 months–18 years who start late or who are >1 month behind — United States, 2007 The table below provides catch-up schedules and minimum intervals between doses for children whose vaccinations have been delayed. A vaccine series does not need to be restarted, regardless of the time that has elapsed between doses. Use the section appropriate for the child’s age. CATCH-UP SCHEDULE FOR PERSONS AGED 4 MONTHS–6 YEARS Minimum age Minimum interval between doses Vaccine for Dose 1 Dose 1 to Dose 2 Dose 2 to Dose 3 Dose 3 to Dose 4 Dose 4 to Dose 5 1 8 weeks Hepatitis B Birth 4 weeks (and 16 weeks after first dose) Rotavirus2 6 weeks 4 weeks 4 weeks Diphtheria, Tetanus, Pertussis3 6 weeks 4 weeks 4 weeks 6 months 6 months3 4 weeks 4 weeks4 if first dose administered at age <12 months if current age <12 months 8 weeks (as final dose) Haemophilus 4 This dose only necessary 8 weeks (as final dose) for children aged 4 8 weeks (as final dose) influenzae 6 weeks if first dose administered at age 12–14 months if current age >12 months and second 12 months–5 years type b dose administered at age <15 months No further doses needed who received 3 doses if first dose administered at age >15 months No further doses needed before age 12 months if previous dose administered at age >15 months 4 weeks if first dose administered at age <12 months 4 weeks and current age <24 months if current age <12 months 8 weeks (as final dose) 8 weeks (as final dose) This dose only necessary 5 8 weeks (as final dose) for children aged Pneumococcal 6 weeks if first dose administered at age >12 months if current age >12 months or current age 24–59 months 12 months–5 years No further doses needed who received 3 doses No further doses needed for healthy children if previous dose before age 12 months for healthy children if first dose administered at age >24 months administered at age >24 months Inactivated Poliovirus6 6 weeks 4 weeks 4 weeks 4 weeks6 Measles, Mumps, Rubella7 12 months 4 weeks Varicella8 12 months 3 months Hepatitis A9 12 months 6 months CATCH-UP SCHEDULE FOR PERSONS AGED 7–18 YEARS Tetanus, Diphtheria/ 8 weeks 10 if first dose administered at age <12 months 6 months Tetanus, Diphtheria, 7 years 4 weeks if first dose administered 10 6 months at age <12 months Pertussis if first dose administered at age >12 months Human Papillomavirus11 9 years 4 weeks 12 weeks Hepatitis A9 12 months 6 months

1 8 weeks Hepatitis B Birth 4 weeks (and 16 weeks after first dose) Inactivated Poliovirus6 6 weeks 4 weeks 4 weeks 4 weeks6 Measles, Mumps, Rubella7 12 months 4 weeks 4 weeks Varicella8 12 months if first dose administered at age >13 years 3 months if first dose administered at age <13 years 1. Hepatitis B vaccine (HepB). (Minimum age: birth) 7. Measles, mumps, and rubella vaccine (MMR). (Minimum age: 12 months) •Administer the 3-dose series to those who were not previously vaccinated. •The second dose of MMR is recommended routinely at age 4–6 years but may • A 2-dose series of Recombivax HB® is licensed for children aged 11–15 years. be administered earlier if desired. 2. Rotavirus vaccine (Rota). (Minimum age: 6 weeks) • If not previously vaccinated, administer 2 doses of MMR during any visit with • Do not start the series later than age 12 weeks. >4 weeks between the doses. • Administer the final dose in the series by age 32 weeks. Do not administer a 8. Varicella vaccine. (Minimum age: 12 months) dose later than age 32 weeks. • The second dose of varicella vaccine is recommended routinely at age • Data on safety and efficacy outside of these age ranges are insufficient. 4–6 years but may be administered earlier if desired. 3. Diphtheria and tetanus toxoids and acellular pertussis vaccine (DTaP). • Do not repeat the second dose in persons aged <13 years if administered (Minimum age: 6 weeks) >28 days after the first dose. • The fifth dose is not necessary if the fourth dose was administered at age >4 years. 9.Hepatitis A vaccine (HepA). (Minimum age: 12 months) • DTaP is not indicated for persons aged >7 years. •HepA is recommended for certain groups of children, including in areas where 4. Haemophilus influenzae type b conjugate vaccine (Hib). (Minimum age: 6w eeks) vaccination programs target older children. See MMWR 2006;55(No. RR-7):1–23. • Vaccine is not generally recommended for children aged >5 years. 10. Tetanus and diphtheria toxoids vaccine (Td) and tetanus and diphtheria • If current age <12 months and the first 2 doses were PRP-OMP (PedvaxHIB® or toxoids and acellular pertussis vaccine (Tdap). (Minimum ages: 7 years for ComVax® [Merck]), the third (and final) dose should be administered at age 12– Td, 10 years for BOOSTRIX ® , and 11 years for ADACEL ™ ) 15 months and at least 8 weeks after the second dose. •Tdap should be substituted for a single dose of Td in the primary catch-up series • If first dose was administered at age 7–11 months, administer 2 doses separated or as a booster if age appropriate; use Td for other doses. by 4 weeks plus a booster at age 12–15 months. •A 5-year interval from the last Td dose is encouraged when Tdap is used as a 5. Pneumococcal conjugate vaccine (PCV). (Minimum age: 6 weeks) booster dose. A booster (fourth) dose is needed if any of the previous doses • Vaccine is not generally recommended for children aged >5 years. were administered at age <12 months. Refer to ACIP recommendations for further 6. Inactivated poliovirus vaccine (IPV). (Minimum age: 6 weeks) information. See MMWR 2006;55(No. RR-3). • For children who received an all-IPV or all-oral poliovirus (OPV) series, a fourth 11. Human papillomavirus vaccine (HPV). (Minimum age: 9 years) dose is not necessary if third dose was administered at age >4 years. •Administer the HPV vaccine series to females at age 13–18 years if not previously • If both OPV and IPV were administered as part of a series, a total of 4 doses vaccinated. should be administered, regardless of the child’s current age.

Information about reporting reactions after immunization is available online at http://www.vaers.hhs.gov or by telephone via the 24-hour national toll-free information line 800-822-7967. Suspected cases of vaccine-preventable diseases should be reported to the state or local health department. Additional information, including precautions and contraindications for immunization, is available from the National Center for Immunization and Respiratory Diseases at http://www.cdc.gov/nip/default.htm or telephone, 800-CDC-INFO (800-232-4636).

154 THE JORDAN REPORT 2007 APPENDIX F

Recommended Adult Immunization Schedule, by Vaccine and Age Group UNITED STATES · OCTOBER 2006–SEPTEMBER 2007

▲ Vaccine ▲ Age group 19–49 years 50–64 years >65 years

Tetanus, diphtheria, 1-dose Td booster every 10 yrs pertussis (Td/Tdap)1,* Substitute 1 dose of Tdap for Td

Human papillomavirus (HPV)2 3 doses (females)

Measles, mumps, rubella (MMR)3,* 1 or 2 doses 1 dose

Varicella4,* 2 doses (0, 4–8 wks) 2 doses (0, 4 – 8 wks)

Influenza5,* 1 dose annually 1 dose annually

Pneumococcal (polysaccharide)6,7 1–2 doses 1 dose

Hepatitis A8,* 2 doses (0, 6 –12 mos, or 0, 6 –18 mos)

Hepatitis B9,* 3 doses (0, 1–2, 4 – 6 mos)

Meningococcal10 1 or more doses

*Covered by the Vaccine Injury Compensation Program. NOTE: These recommendations must be read with the footnotes (see reverse). For all persons in this category who meet the age Recommended if some other risk factor is requirements and who lack evidence of immunity present (e.g., on the basis of medical, (e.g., lack documentation of vaccination or have occupational, lifestyle, or other indications) no evidence of prior infection)

This schedule indicates the recommended age groups and medical indications for routine administration of currently licensed vaccines for persons aged >19 years, as of October 1, 2006. Licensed combination vaccines may be used whenever any components of the combination are indicated and when the vaccine’s other components are not contraindicated. For detailed recommendations on all vaccines, including those used primarily for travelers or that are issued during the year, consult the manufacturers’ package inserts and the complete statements from the Advisory Committee on Immunization Practices (www.cdc.gov/nip/publications/acip-list.htm). Report all clinically significant postvaccination reactions to the Vaccine Adverse Event Reporting System (VAERS). Reporting forms and instructions on filing a VAERS report are available at www.vaers.hhs.gov or by telephone, 800-822-7967. Information on how to file a Vaccine Injury Compensation Program claim is available at www.hrsa.gov/vaccinecompensation or by telephone, 800-338-2382. To file a claim for vaccine injury, contact the U.S. Court of Federal Claims, 717 Madison Place, N.W., Washington, D.C. 20005; telephone, 202-357-6400. Additional information about the vaccines in this schedule and contraindications for vaccination is also available at www.cdc.gov/nip or from the CDC-INFO Contact Center at 800-CDC-INFO (800-232-4636) in English and Spanish, 24 hours a day, 7 days a week.

Recommended Adult Immunization Schedule, by Vaccine and Medical and Other Indications UNITED STATES · OCTOBER 2006–SEPTEMBER 2007

Congenital immunodeficiency, 11 leukemia, 11 lymphoma, Asplenia generalized Diabetes, (including Chronic liver Kidney failure, elective Human

▲ end-stage renal malignancy, heart disease, disease, immunodeficiency Indication Pregnancy cerebrospinal fluid chronic splenectomy recipients of disease, Healthcare and terminal recipients of virus (HIV) workers leaks; therapy with pulmonary disease, clotting factor infection3,11 alkylating agents, chronic alcoholism complement concentrates hemodialysis antimetabolites, component

radiation, or high- deficiencies) ▲ dose, long-term Vaccine corticosteroids Tetanus, diphtheria, 1-dose Td booster every 10 yrs pertussis (Td/Tdap)1,* Substitute 1 dose of Tdap for Td

Human papillomavirus (HPV)2 3 doses for females through age 26 yrs (0, 2, 6 mos)

Measles, mumps, rubella (MMR)3,* 1 or 2 doses

Varicella4,* 2 doses (0, 4–8 wks) 2 doses

APPENDIX5, F 1 dose 155 Influenza * 1 dose annually annually 1 dose annually

Pneumococcal (polysaccharide)6,7 1–2 doses 1–2 doses 1–2 doses

Hepatitis A8,* 2 doses (0, 6 –12 mos, or 0, 6 –18 mos) 2 doses 2 doses (0, 6–12 mos, or 0, 6–18 mos)

Hepatitis B9,* 3 doses (0, 1–2, 4–6 mos) 3 doses (0, 1–2, 4–6 mos)

Meningococcal10 1 dose 1 dose 1 dose

*Covered by the Vaccine Injury Compensation Program. NOTE: These recommendations must be read with the footnotes (see reverse). For all persons in this category who meet the age Recommended if some other risk factor is Contraindicated requirements and who lack evidence of immunity present (e.g., on the basis of medical, (e.g., lack documentation of vaccination or have occupational, lifestyle, or other indications) Approved by no evidence of prior infection) the Advisory Committee on Immunization Practices, the American College of Obstetricians and Gynecologists, Department of Health and Human Services the American Academy of Family Physicians, Centers for Disease Control and Prevention and the American College of Physicians Recommended Adult Immunization Schedule, by Vaccine and Age Group UNITED STATES · OCTOBER 2006–SEPTEMBER 2007

▲ Vaccine ▲ Age group 19–49 years 50–64 years >65 years

Tetanus, diphtheria, 1-dose Td booster every 10 yrs pertussis (Td/Tdap)1,* Substitute 1 dose of Tdap for Td

Human papillomavirus (HPV)2 3 doses (females)

Measles, mumps, rubella (MMR)3,* 1 or 2 doses 1 dose

Varicella4,* 2 doses (0, 4–8 wks) 2 doses (0, 4–8 wks)

Influenza5,* 1 dose annually 1 dose annually

Pneumococcal (polysaccharide)6,7 1–2 doses 1 dose

Hepatitis A8,* 2 doses (0, 6 –12 mos, or 0, 6 –18 mos)

Hepatitis B9,* 3 doses (0, 1–2, 4–6 mos)

Meningococcal10 1 or more doses

*Covered by the Vaccine Injury Compensation Program. NOTE: These recommendations must be read with the footnotes (see reverse). For all persons in this category who meet the age Recommended if some other risk factor is requirements and who lack evidence of immunity present (e.g., on the basis of medical, (e.g., lack documentation of vaccination or have occupational, lifestyle, or other indications) no evidence of prior infection)

This schedule indicates the recommended age groups and medical indications for routine administration of currently licensed vaccines for persons aged >19 years, as of October 1, 2006. Licensed combination vaccines may be used whenever any components of the combination are indicated and when the vaccine’s other components are not contraindicated. For detailed recommendations on all vaccines, including those used primarily for travelers or that are issued during the year, consult the manufacturers’ package inserts and the complete statements from the Advisory Committee on Immunization Practices (www.cdc.gov/nip/publications/acip-list.htm). Report all clinically significant postvaccination reactions to the Vaccine Adverse Event Reporting System (VAERS). Reporting forms and instructions on filing a VAERS report are available at www.vaers.hhs.gov or by telephone, 800-822-7967. Information on how to file a Vaccine Injury Compensation Program claim is available at www.hrsa.gov/vaccinecompensation or by telephone, 800-338-2382. To file a claim for vaccine injury, contact the U.S. Court of Federal Claims, 717 Madison Place, N.W., Washington, D.C. 20005; telephone, 202-357-6400. Additional information about the vaccines in this schedule and contraindications for vaccination is also available at www.cdc.gov/nip or from the CDC-INFO Contact Center at 800-CDC-INFO (800-232-4636) in English and Spanish, 24 hours a day, 7 days a week.

Recommended Adult Immunization Schedule, by Vaccine and Medical and Other Indications UNITED STATES · OCTOBER 2006–SEPTEMBER 2007

Congenital immunodeficiency, 11 leukemia, 11 lymphoma, Asplenia generalized Diabetes, (including Chronic liver Kidney failure, elective Human

▲ end-stage renal malignancy, heart disease, disease, immunodeficiency Indication Pregnancy cerebrospinal fluid chronic splenectomy recipients of disease, Healthcare and terminal recipients of virus (HIV) workers leaks; therapy with pulmonary disease, clotting factor infection3,11 alkylating agents, chronic alcoholism complement concentrates hemodialysis antimetabolites, component

radiation, or high- deficiencies) ▲ dose, long-term Vaccine corticosteroids Tetanus, diphtheria, 1-dose Td booster every 10 yrs pertussis (Td/Tdap)1,* Substitute 1 dose of Tdap for Td

Human papillomavirus (HPV)2 3 doses for females through age 26 yrs (0, 2, 6 mos)

Measles, mumps, rubella (MMR)3,* 1 or 2 doses

Varicella4,* 2 doses (0, 4–8 wks) 2 doses

5, 1 dose Influenza * 1 dose annually annually 1 dose annually

Pneumococcal (polysaccharide)6,7 1–2 doses 1–2 doses 1–2 doses

Hepatitis A8,* 2 doses (0, 6 – 12 mos, or 0, 6 – 18 mos) 2 doses 2 doses (0, 6 – 12 mos, or 0, 6 – 18 mos)

Hepatitis B9,* 3 doses (0, 1–2, 4 – 6 mos) 3 doses (0, 1–2, 4–6 mos)

Meningococcal10 1 dose 1 dose 1 dose

*Covered by the Vaccine Injury Compensation Program. NOTE: These recommendations must be read with the footnotes (see reverse). For all persons in this category who meet the age Recommended if some other risk factor is Contraindicated requirements and who lack evidence of immunity present (e.g., on the basis of medical, (e.g., lack documentation of vaccination or have occupational, lifestyle, or other indications) Approved by no evidence of prior infection) the Advisory Committee on Immunization Practices, the American College of Obstetricians and Gynecologists, Department of Health and Human Services the American Academy of Family Physicians, Centers for Disease Control and Prevention and the American College of Physicians

156 THE JORDAN REPORT 2007 Footnotes Recommended Adult Immunization Schedule · UNITED STATES, OCTOBER 2006–SEPTEMBER 2007 1. Tetanus, diphtheria, and acellular pertussis (Td/Tdap) vaccination. Adults aspiration (e.g., cognitive dysfunction, spinal cord injury, or seizure disorder or other with uncertain histories of a complete primary vaccination series with diphtheria and neuromuscular disorder); and pregnancy during the influenza season. No data exist on the tetanus toxoid–containing vaccines should begin or complete a primary vaccination series. risk for severe or complicated influenza disease among persons with asplenia; however, A primary series for adults is 3 doses; administer the first 2 doses at least 4 weeks apart influenza is a risk factor for secondary bacterial infections that can cause severe disease and the third dose 6–12 months after the second. Administer a booster dose to adults who among persons with asplenia. Occupational indications: healthcare workers and employees have completed a primary series and if the last vaccination was received >10 years of long-term–care and assisted living facilities. Other indications: residents of nursing homes previously. Tdap or tetanus and diphtheria (Td) vaccine may be used; Tdap should replace a and other long-term–care and assisted living facilities; persons likely to transmit influenza to single dose of Td for adults aged <65 years who have not previously received a dose of persons at high risk (e.g., in-home household contacts and caregivers of children aged Tdap (either in the primary series, as a booster, or for wound management). Only one of two 0–59 months, or persons of all ages with high-risk conditions); and anyone who would like Tdap products (Adacel® [sanofi pasteur]) is licensed for use in adults. If the person is to be vaccinated. Healthy, nonpregnant persons aged 5–49 years without high-risk medical pregnant and received the last Td vaccination >10 years previously, administer Td during conditions who are not contacts of severely immunocompromised persons in special care the second or third trimester; if the person received the last Td vaccination in <10 years, units can receive either intranasally administered influenza vaccine (FluMist®) or inactivated administer Tdap during the immediate postpartum period. A one-time administration of vaccine. Other persons should receive the inactivated vaccine. 1 dose of Tdap with an interval as short as 2 years from a previous Td vaccination is recommended for postpartum women, close contacts of infants aged <12 months, 6. Pneumococcal polysaccharide vaccination. Medical indications: chronic disorders and all healthcare workers with direct patient contact. In certain situations, Td can be of the pulmonary system (excluding asthma); cardiovascular diseases; diabetes mellitus; deferred during pregnancy and Tdap substituted in the immediate postpartum period, or chronic liver diseases, including liver disease as a result of alcohol abuse (e.g., cirrhosis); Tdap can be given instead of Td to a pregnant woman after an informed discussion with the chronic renal failure or nephrotic syndrome; functional or anatomic asplenia (e.g., sickle cell woman (see www.cdc.gov/nip/publications/acip-list.htm). Consult the ACIP statement for disease or splenectomy [if elective splenectomy is planned, vaccinate at least 2 weeks recommendations for administering Td as prophylaxis in wound management before surgery]); immunosuppressive conditions (e.g., congenital immunodeficiency, HIV (www.cdc.gov/mmwr/preview/mmwrhtml/00041645.htm). infection [vaccinate as close to diagnosis as possible when CD4 cell counts are highest], leukemia, lymphoma, multiple myeloma, Hodgkin disease, generalized malignancy, or organ 2. Human papillomavirus (HPV) vaccination. HPV vaccination is recommended for all or bone marrow transplantation); chemotherapy with alkylating agents, antimetabolites, or women aged <26 years who have not completed the vaccine series. Ideally, vaccine should high-dose, long-term corticosteroids; and cochlear implants. Other indications: Alaska be administered before potential exposure to HPV through sexual activity; however, women Natives and certain American Indian populations and residents of nursing homes or other who are sexually active should still be vaccinated. Sexually active women who have not long-term–care facilities. been infected with any of the HPV vaccine types receive the full benefit of the vaccination. Vaccination is less beneficial for women who have already been infected with one or more 7. Revaccination with pneumococcal polysaccharide vaccine. One-time of the four HPV vaccine types. A complete series consists of 3 doses. The second dose revaccination after 5 years for persons with chronic renal failure or nephrotic syndrome; should be administered 2 months after the first dose; the third dose should be administered functional or anatomic asplenia (e.g., sickle cell disease or splenectomy); 6 months after the first dose. Vaccination is not recommended during pregnancy. If a immunosuppressive conditions (e.g., congenital immunodeficiency, HIV infection, leukemia, woman is found to be pregnant after initiating the vaccination series, the remainder of the lymphoma, multiple myeloma, Hodgkin disease, generalized malignancy, or organ or bone 3-dose regimen should be delayed until after completion of the pregnancy. marrow transplantation); or chemotherapy with alkylating agents, antimetabolites, or high- dose, long-term corticosteroids. For persons aged >65 years, one-time revaccination if they 3. Measles, mumps, rubella (MMR) vaccination. Measles component: adults born were vaccinated >5 years previously and were aged <65 years at the time of before 1957 can be considered immune to measles. Adults born during or after 1957 should primary vaccination. receive >1 dose of MMR unless they have a medical contraindication, documentation of >1 dose, history of measles based on healthcare provider diagnosis, or laboratory evidence 8. Hepatitis A vaccination. Medical indications: persons with chronic liver disease and of immunity. A second dose of MMR is recommended for adults who 1) have been recently persons who receive clotting factor concentrates. Behavioral indications: men who have sex exposed to measles or in an outbreak setting; 2) have been previously vaccinated with killed with men and persons who use illegal drugs. Occupational indications: persons working with measles vaccine; 3) have been vaccinated with an unknown type of measles vaccine during hepatitis A virus (HAV)–infected primates or with HAV in a research laboratory setting. 1963–1967; 4) are students in postsecondary educational institutions; 5) work in Other indications: persons traveling to or working in countries that have high or intermediate ahealthcare facility; or 6) plan to travel internationally. Withhold MMR or other measles- endemicity of hepatitis A (a list of countries is available at www.cdc.gov/travel/diseases.htm) containing vaccines from HIV-infected persons with severe immunosuppression. and any person who would like to obtain immunity. Current vaccines should be administered

Mumps component: adults born before 1957 can generally be considered immune to in a 2-dose schedule at either 0 and 6–12 months, or 0 and 6–18 months. If the combined mumps. Adults born during or after 1957 should receive 1 dose of MMR unless they have a hepatitis A and hepatitis B vaccine is used, administer 3 doses at 0, 1, and 6 months. medical contraindication, history of mumps based on healthcare provider diagnosis, or laboratory evidence of immunity. A second dose of MMR is recommended for adults who 9. Hepatitis B vaccination. Medical indications: persons with end-stage renal disease, 1) are in an age group that is affected during a mumps outbreak; 2) are students in including patients receiving hemodialysis; persons seeking evaluation or treatment for a postsecondary educational institutions; 3) work in a healthcare facility; or 4) plan to travel sexually transmitted disease (STD); persons with HIV infection; persons with chronic liver internationally. For unvaccinated healthcare workers born before 1957 who do not have disease; and persons who receive clotting factor concentrates. Occupational indications: other evidence of mumps immunity, consider giving 1 dose on a routine basis and strongly healthcare workers and public-safety workers who are exposed to blood or other potentially consider giving a second dose during an outbreak. Rubella component: administer 1 dose of infectious body fluids. Behavioral indications: sexually active persons who are not in a long- MMR vaccine to women whose rubella vaccination history is unreliable or who lack term, mutually monogamous relationship (i.e., persons with >1 sex partner during the laboratory evidence of immunity. For women of childbearing age, regardless of birth year, previous 6 months); current or recent injection-drug users; and men who have sex with routinely determine rubella immunity and counsel women regarding congenital rubella men. Other indications: household contacts and sex partners of persons with chronic syndrome. Do not vaccinate women who are pregnant or who might become pregnant hepatitis B virus (HBV) infection; clients and staff members of institutions for persons with within 4 weeks of receiving vaccine. Women who do not have evidence of immunity should developmental disabilities; all clients of STD clinics; international travelers to countries with receive MMR vaccine upon completion or termination of pregnancy and before discharge high or intermediate prevalence of chronic HBV infection (a list of countries is available at from the healthcare facility. www.cdc.gov/travel/diseases.htm); and any adult seeking protection from HBV infection. Settings where hepatitis B vaccination is recommended for all adults: STD treatment 4. Varicella vaccination. All adults without evidence of immunity to varicella should facilities; HIV testing and treatment facilities; facilities providing drug-abuse treatment and receive 2 doses of varicella vaccine. Special consideration should be given to those who prevention services; healthcare settings providing services for injection-drug users or men 1) have close contact with persons at high risk for severe disease (e.g., healthcare workers who have sex with men; correctional facilities; end-stage renal disease programs and and family contacts of immunocompromised persons) or 2) are at high risk for exposure or facilities for chronic hemodialysis patients; and institutions and nonresidential daycare transmission (e.g., teachers of young children; child care employees; residents and staff facilities for persons with developmental disabilities. Special formulation indications: for adult members of institutional settings, including correctional institutions; college students; patients receiving hemodialysis and other immunocompromised adults, 1 dose of 40 µg/mL military personnel; adolescents and adults living in households with children; nonpregnant (Recombivax HB®) or 2 doses of 20 µg/mL (Engerix-B®). women of childbearing age; and international travelers). Evidence of immunity to varicella in adults includes any of the following: 1) documentation of 2 doses of varicella vaccine at 10.Meningococcal vaccination. Medical indications: adults with anatomic or functional least 4 weeks apart; 2) U.S.-born before 1980 (although for healthcare workers and pregnant asplenia, or terminal complement component deficiencies. Other indications: first-year women, birth before 1980 should not be considered evidence of immunity); 3) history of college students living in dormitories; microbiologists who are routinely exposed to isolates varicella based on diagnosis or verification of varicella by a healthcare provider (for a patient of Neisseria meningitidis; military recruits; and persons who travel to or live in countries in reporting a history of or presenting with an atypical case, a mild case, or both, healthcare which meningococcal disease is hyperendemic or epidemic (e.g., the “meningitis belt” of providers should seek either an epidemiologic link with a typical varicella case or evidence sub-Saharan Africa during the dry season [December–June]), particularly if their contact of laboratory confirmation, if it was performed at the time of acute disease); 4) history of with local populations will be prolonged. Vaccination is required by the government of Saudi herpes zoster based on healthcare provider diagnosis; or 5) laboratory evidence of immunity Arabia for all travelers to Mecca during the annual Hajj. Meningococcal conjugate vaccine or laboratory confirmation of disease. Do not vaccinate women who are pregnant or might is preferred for adults with any of the preceding indications who are aged <55 years, become pregnant within 4 weeks of receiving the vaccine. Assess pregnant women for although meningococcal polysaccharide vaccine (MPSV4) is an acceptable alternative. evidence of varicella immunity. Women who do not have evidence of immunity should Revaccination after 5 years might be indicated for adults previously vaccinated with receive dose 1 of varicella vaccine upon completion or termination of pregnancy and before MPSV4 who remain at high risk for infection (e.g., persons residing in areas in which discharge from the healthcare facility. Dose 2 should be administered 4–8 weeks disease is epidemic). after dose 1. 11.Selected conditions for which Haemophilus influenzae type b (Hib) vaccine may be used. Hib conjugate vaccines are licensed for children aged 5. Influenza vaccination. Medical indications: chronic disorders of the cardiovascular or 6 weeks–71 months. No efficacy data are available on which to base a recommendation pulmonary systems, including asthma; chronic metabolic diseases, including diabetes concerning use of Hib vaccine for older children and adults with the chronic conditions mellitus, renal dysfunction, hemoglobinopathies, or immunosuppression (including associated with an increased risk for Hib disease. However, studies suggest good immunosuppression caused by medications or HIV); any condition that compromises immunogenicity in patients who have sickle cell disease, leukemia, or HIV infection or who respiratory function or the handling of respiratory secretions or that can increase the risk of have had splenectomies; administering vaccine to these patients is not contraindicated.

Use of trade names and commercial sources is for identification only and does not imply endorsement by the U.S. Department of Health and Human Services.

APPENDIX F 157

U. S. DEPARTMENT OF HEALTH AND HUMAN SERVICES National Institutes of Health National Institute of Allergy and Infectious Diseases NIH Publication No. 06-6057 May 2007 www.niaid.nih.gov