RESPOND Lessons Learned from Emergency Response Vaccination Efforts for Cholera, Typhoid, Yellow Fever, and Ebola Jenny A. Walldorf, Kashmira A. Date, Nandini Sreenivasan, Jennifer B. Harris, Terri B. Hyde Countries must be prepared to respond to public health possibility of international spread and thereby enhancing threats associated with emergencies, such as natural di- global health security. sasters, sociopolitical conflicts, or uncontrolled disease For countries to respond rapidly in emergency situa- outbreaks. Rapid vaccination of populations vulnerable to tions, planning for appropriate and effective vaccine deliv- epidemic-prone vaccine-preventable diseases is a major ery to at-risk populations is essential. The decision to en- component of emergency response. Emergency vaccina- gage in a vaccination response depends on several factors, tion planning presents challenges, including how to pre- dict resource needs, expand vaccine availability during including the risk for a VPD in the emergency situation, global shortages, and address regulatory barriers to de- characteristics and availability of vaccines for response, liver new products. The US Centers for Disease Control and prioritization of vaccination in relation to other public and Prevention supports countries to plan, implement, health interventions (1). Once a decision is made for a vac- and evaluate emergency vaccination response. We de- cination response, additional issues need to be addressed, scribe work of the Centers for Disease Control and Pre- including regulatory barriers for unlicensed products, vac- vention in collaboration with global partners to support cine supply and stockpile access, appropriate cold chain ca- emergency vaccination against cholera, typhoid, yellow pacity, and designation of roles and responsibilities based fever, and Ebola, diseases for which a new vaccine or on in-country capacity and global partner involvement. vaccine formulation has played a major role in response. Key responsibilities include overall emergency manage- Lessons learned will help countries prepare for future ment, coordination of vaccination response, communica- emergencies. Integration of vaccination with emergency response augments global health security through reduc- tions and social mobilization, monitoring and evaluation of ing disease burden, saving lives, and preventing spread vaccine implementation, and enhancement of surveillance across international borders. for adverse events after immunization. To enable countries to respond rapidly to future emergencies, clearly outlining the command structure beforehand for these key responsi- n emergency settings, countries must be prepared to bilities is essential. Irespond to public health threats. Prompt vaccine deliv- Evaluation of emergency vaccination activities is a ery can be a major component of emergency response, major component of the overall response efforts, necessary especially for populations vulnerable to epidemic-prone, to refine ongoing activities and document lessons learned. vaccine-preventable diseases (VPDs). Public health emer- Implementation research can close evidence gaps between gencies might be triggered by natural disaster; humanitar- licensure and programmatic use of new vaccines (2). Emer- ian emergency; a disease pandemic leading to health sys- gency vaccination has been well-described and evaluated tems breakdown, as in the recent Ebola epidemic in West for outbreak-prone VPDs such as polio, measles, meningi- Africa in 2014; or by a specific VPD outbreak not con- tis, yellow fever, cholera, and hepatitis A (3). However, as tained by ongoing immunization services. During emer- new vaccines, new formulations, or new routes of admin- gencies affecting health systems in general, vaccination istration for existing vaccines are developed, licensed, and services are frequently disrupted. Emergency vaccination prequalified by the World Health Organization (WHO), campaigns aim to control VPD outbreaks, reducing the vaccination strategies must be evaluated and reevaluated to ensure the greatest effect for protecting vulnerable popula- Author affiliations: Centers for Disease Control and Prevention, tions and preventing spread of disease. Atlanta, Georgia, USA The Global Immunization Division in the Center DOI: https://doi.org/10.3201/eid2313.170550 for Global Health at the Centers for Disease Control and S210 Emerging Infectious Diseases • www.cdc.gov/eid • Vol. 23, Supplement to December 2017 Lessons Learned from Emergency Response Vaccination Prevention (CDC) is committed to supporting countries in of Shanchol showed an efficacy of 63% against severely emergency vaccine delivery planning, implementation, and dehydrating cholera in the short term (6 months), which has evaluation in collaboration with other CDC divisions and major implications for outbreak control (13). with international partners. In this report, we highlight the CDC has conducted several evaluations of OCV use work CDC has conducted to generate evidence that will in emergency settings. In 2010, CDC collaborated with shape future outbreak response vaccination strategies by partners including WHO, the Pan American Health Orga- using lessons learned specifically from cholera, typhoid, nization, and others to review current evidence for OCV yellow fever, and Ebola. For these diseases, a new vac- use in emergency settings and conduct real-time modeling cine or new vaccine formulation has played a major role in to estimate the effect of using a limited supply of avail- emergency response. Lessons learned will help countries able OCV doses during a cholera outbreak in Haiti after prepare for future emergency outbreak response and con- the 2012 earthquake (14). In the postemergency period in tribute to the broader goal of more rapidly containing pub- Haiti, CDC conducted additional evaluations of the cholera lic health emergencies caused by VPDs, thereby enhancing response to inform future vaccination campaigns. These global health security. evaluations included OCV coverage surveys and precam- paign and postcampaign knowledge, attitude, and prac- Cholera tice (KAP) surveys (15,16). A postcampaign KAP survey Cholera is an acute diarrheal infection caused by inges- showed an increase in availability of soap and handwash- tion of toxigenic serogroups O1 and O139 of the bacte- ing stations but a decrease in reported treatment of drinking rium Vibrio cholerae. The global burden of cholera is water, highlighting the need for comprehensive communi- estimated to be 2.9 million cases and 95,000 deaths annu- cation messages for cholera control during and, if feasible, ally; most cases are reported to WHO from sub-Saharan after OCV campaigns. Africa (4). More recently, since 2010, Haiti has made a In 2013, CDC supported the Thailand Ministry of Pub- major contribution to the global burden. Although chol- lic Health in implementing and evaluating a preemptive era prevention and control measures have traditionally 2-dose OCV campaign in a refugee camp. Coverage and focused on cholera treatment and improving access to precampaign and postcampaign KAP surveys showed a safe water, sanitation, and hygiene (WaSH), oral chol- high degree of acceptability of the campaign, as well as im- era vaccines (OCVs) have gained prominence as a major provements in WaSH behaviors (17,18). In 2015, a 2-dose complementary tool in comprehensive cholera prevention OCV campaign was conducted in Iraq in response to a and control. In 2010, WHO recommended the use of ex- cholera outbreak affecting ≈255,000 persons living in se- isting OCVs, preemptively in cholera-endemic settings to lected refugee camps, internally displaced persons camps, target high-risk areas or populations or reactively as part and collective centers. After the campaign, CDC conducted of outbreak response activities (5). In June 2013, WHO a coverage survey in collaboration with WHO and the Iraq established a global OCV stockpile with an initial stock of Ministry of Health; overall, 2-dose coverage was 87%, and 2 million doses with funding from multiple partners (6). 55% of respondents reported receiving other cholera pre- In November 2013, the Global Alliance for Vaccines and vention messages (19). This evaluation demonstrated the Immunization endorsed funding support for the stockpile feasibility of successfully implementing an OCV vaccina- for 2014–2018 (7). As of March 2017, a total of 41 OCV tion campaign in a conflict setting as part of an integrated campaigns have been conducted in 14 countries with vac- approach to cholera control. cine from the global stockpile (8). Most recently, 1 million doses of Euvichol were re- Three inactivated, whole-cell OCVs are prequalified leased for use in hurricane-affected departments in Haiti by WHO and available for global use: Dukoral (killed after Hurricane Matthew in October 2016, the first release whole-cell monovalent [O1] cholera vaccine with cholera of Euvichol from the global stockpile. Approximately toxin B subunit; Valneva, Lyon, France); Shanchol (modi- 830,000 persons in 18 communes were targeted for vacci- fied killed bivalent [O1 and O139] whole-cell–only cholera nation with a single dose, the largest single-dose campaign vaccines; (Shantha Biotechnics, Hyderabad, India); and as well as the largest emergency stockpile release to date. Euvichol (modified killed bivalent [O1 and O139] whole- CDC was part of the Haiti OCV taskforce that led monitor- cell–only cholera vaccines; Eubiologics, Seoul, South Ko- ing and evaluation of the