The economic evaluation of human papillomavirus vaccination strategies against cervical cancer in women in Lao PDR: a mathematical modelling approach Phetsavanh Chanthavilay1,2*, Daniel Reinharz2,3, Mayfong Mayxay1,4,5, Keokedthong Phongsavan6, Donald E Marsden5, Lynne Moore2 and Lisa J White7,8 1Faculty of Postgraduate Studies, University of Health Sciences, Vientiane, Lao PDR, 2Department of Social and Preventive Medicine, Faculty of Medicine, Laval University. Quebec, Canada, 3Institut de la Francophonie pour la Médecine tropicale, Vientiane, Lao PDR, 4Lao-Oxford-Mahosot Hospital-Wellcome Trust Research Unit (LOMWRU), Microbiology Laboratory, Mahosot Hospital, Vientiane, Lao PDR, 5Centre for Tropical Medicine and Global Health, Churchill Hospital, University of Oxford, Oxford, UK., 6Gynecologic Oncology Unit, Setthathirath Hospital, Vientiane, Lao PDR., 7Mahidol-Oxford Tropical Medicine Research Unit, Faculty of Tropical Medicine, Mahidol University, Bangkok, Thailand, 8Nuffield Department of Medicine, University of Oxford, Oxford, UK Contact - Phetsavanh Chanthavilay: [email protected] Background: Cervical cancer, a preventable disease, is the third leading cause of cancer morbidity and mortality in the Lao People’s Democratic Republic (Lao PDR). Since many cervical cancers are linked to human papilloma virus (HPV) infection, vaccination against this virus may lead to a reduction in these types of cancer. The study described here is the first to compare the cost-effectiveness of different HPV vaccination options in Lao PDR. Methods: A dynamic compartment model was created. The model included routine screening activities already in place, as well as theoretical interventions that included a 10-year-old girl-only vaccination programme combined with/without a 10-year-old boy vaccination programme and/or a catch-up component. The simulation was run over 100 years. In base case analyses, we assumed 70% vaccination coverage with lifelong protection and 100% efficacy against HPV types 16/18. The outcomes of interest were the incremental cost per Disability-Adjusted Life Year (DALY) averted. Results: In base case analyses, according to the WHO definition of cost-effectiveness thresholds, vaccinating 10- year-old girls was very cost-effective. Adding a catch-up vaccination element for females aged 11-25 years was also very cost-effective, costing 1,559 international dollars (I$) per DALY averted. Increasing the age limit of the catch-up vaccination component to 75 years old showed that this remained a cost-effective option (I$ 5,840 per DALY averted). Adding a vaccination programme for 10-year-old boys was not found to be cost-effective unless a short time simulation (30 years or less) was considered, along with a catch-up vaccination component for both males and females. Conclusions: Adding a catch-up female vaccination component is more attractive than adding a 10-year-old boy vaccination component. Key words: Economic evaluation, HPV vaccination, cervical cancer and Lao PDR. Low immunogenicity of pentavalent childhood vaccine in Lao People’s Democratic Republic Konstantin Evdokimov1,2, Phonethipsavanh Nouanthong1, Lisa Hefele1,2, Kong Sayasinh3, Keooudomphone Vilivong1, Bounthome Samountry4, Darouny Phonekeo5, Michel Strobel3, Frank Haegeman6, Peter Heiman6, Claude P Muller1,2, Antony P Black1 1Lao-Lux Laboratory, Institut Pasteur du Laos, Vientiane, Lao PDR, 2Department of Infection and Immunity, Luxembourg Institute of Health, Esch-sur-Alzette, Grand-Duchy of Luxembourg, 3Institut de la Francophonie pour la Médecine Tropicale, Vientiane, Lao PDR, 4Department of Pathology, Faculty of Medicine, University of Health Sciences, Vientiane, Lao PDR, 5Institut Pasteur du Laos, Vientiane, Lao PDR, 6Luxembourg Development Cooperation Agency, Vientiane, Lao PDR Contact - Antony Black: [email protected] Introduction: In Lao People’s Democratic Republic (PDR), outbreaks of vaccine-preventable infectious diseases such as diphtheria and measles are common and hepatitis B remains endemic. Such high burden of disease can result from not only low vaccination coverage but also low immune response to vaccine. This study was done to determine the immune response to the pentavalent diphtheria–tetanus–whole cell pertussis–hepatitis B– Haemophilus influenzae type b (DTPw–HepB–Hib) vaccine in Lao children after documented vaccination with three doses. Methods: 1131 mother-child pairs were recruited from three provinces in Lao PDR. Children were aged 9-50 months and all had records of at least three injections of the pentavalent vaccine. Serum was analysed by ELISA for HBsAg, anti-HBs, anti-HBc, anti-diphtheria, anti-tetanus, anti-Hib and anti-pertussis antibodies. Demographic and nutritional information were obtained in addition to stool samples for detection of parasites. Results: Protective levels of antibodies against hepatitis B virus (HBV) were found in only 37.9% of children; 55.6%, 85.2% and 57.9% of children were seroprotected against diphtheria, tetanus and Hib, respectively. 23.5% of the children had antibody levels indicating vaccination or exposure to pertussis. Time since vaccination or age, home-birth, malnutrition and location could partially explain the poor vaccine responses. Conclusions: In Lao children with a full documented course of childhood pentavalent vaccination, seroprotective rates are very low. Although it was not possible to fully explain the reasons for low responses they could include malnutrition, parasite infestation and vaccine management. Thus, besides coverage, vaccine immunogenicity is of major concern in Lao PDR. 3 Keywords. Vaccine, immunogenicity, hepatitis Measles seroprevalence survey in Sri Lanka: Evidence of herd immunity for a national policy to protect infants Deepa Gamage, Samitha Ginige, Paba Palihawadana Epidemiology Unit, Ministry of Health, Sri Lanka Contact - Deepa Gamage: [email protected] Introduction: Sri Lanka has experienced an outbreak of measles since 2013 to 2015, despite the high vaccination coverage (MMR vaccination at ages 1 and 3 years). Majority of scattered cases were in bipolar age distribution as of infants and above 40 years. Though maternal antibodies are expected to provide protection for infants, high proportion of reported cases were among 6-11 month infants. In this background a measles serological survey was carried out to assess the measles herd immunity with the objective to assess community level serological protection to measles virus among different age categories Methods: A descriptive cross-sectional study (in districts of Colombo, Monaragala, Anuradhapura and Vavuniya) was conducted among a total of 800 study subjects. Sample size was separately calculated for each selected age category and was 100 in each and 200 for 30-39 age category (expected prevalence 90% except 50% for 30-39 years, precession 7%, design effect 1.5) subjects of selected age groups (6-8 months, 9-11 months,2 years,5 years,15-16 years,20-29 years and 30-39 years) was carried out using multistage cluster sampling technique. Venous blood sample (2ml) was collected and tested for presence of serum anti-measles immunoglobulin (Ig) G antibody levels using ELISA method. Socio-demographic and anthropometric information were collected by using interviewer administered questionnaire and by physical examination. Test results of measles IgG antibody level >200mIU/ml were considered as protective levels. Results: All enrolled (n=800) subjects completed the study and none response rate was 0%. Sero-protective proportion among 6-9 months and 9-11 months groups (prior to measles vaccination) were 2% and 1% respectively indicating they were unprotected for measles. Sero-protective proportion among ages 2, 5, 15-16, 20-29 and 30-39 years were 100%, 98% , 84% , 94% and 98% respectively indicating high population protection. After excluding infants, overall population protection was 95.2% (95% CI 93-96.7%). This illustrates the required measles herd immunity threshold (92-94%) which is maintained to prevent community transmission. Median antibody titre among all study subjects (n=800, including vaccination not recommended population) was 622 mIU/ml (IQR 105.5-1361.2 mIU/ml) and median antibody titre among vaccination due population (n=600) was 735 mIU/ml (IQR 462.9-1667.8 mIU/ml). No significant association of sero-prevalence and nutritional status was observed. Conclusions: Infants of 6-11 months were not adequately protected against measles due to inadequate maternal antibodies and early measles vaccination (MCV) before 1 year would be required to protect infants and to prevent continuation of the measles outbreak. (This recommendation led to the national policy decision of schedule change of MMR vaccine from 1 year to 9 months) Keywords: IQR-interquartile range, CI-confidence interval,ELISA-Enzyme Linked Immunosorbant assay, MMR- Mumps, Measles, Rubella vaccine) An open Label, randomised controlled non-inferiority trial, comparing two-dose priming with the 10- valent pneumococcal conjugate vaccine at 6 and 10 weeks to 6 and 14 weeks in Nepali children Meeru Gurung1, Rama Kandasamy2, Stephen Thorson1, Shrijana Shrestha1, Imran Ansari1, Ganesh Shah1, Pratistha Maskey1, Manisha K.C1, Sarah Kelly2, Katherine L. O'Brien5, Ly-Mee Yu6, Ushma Galal6, David R. Murdoch3, Dominic F. Kelly2, 4, Andrew J. Pollard2, 4 1Paediatric Research Unit, Patan Academy of Health Sciences, Kathmandu, Nepal, 2Oxford Vaccine Group, Department of Paediatrics, University of Oxford, Oxford, United Kingdom, 3Department of Pathology,