Adult hepatitis B vaccination coverage and infection prevalence in Lagos, Nigeria: findings from a facility-based world hepatitis day study

Abstract Background Hepatitis B virus (HBV) infection is a vaccine-preventable disease, and the Global Health Sector Strategy on Viral Hepatitis aims to eliminate viral hepatitis as a public health threat by 2030. Vaccination is prioritized as a key intervention for achieving this goal. The Nigerian Institute of Medical Research (NIMR) conducts annual World Hepatitis Day campaigns to increase awareness and promote HBV prevention in line with global elimination efforts. This study assessed the impact and uptake of an HBV vaccination programme implemented at NIMR and identified strategies to improve adult vaccination uptake in Nigeria. Method A free HBV screening and vaccination programme was conducted for community members between 28 July 2015 and February 2016 as part of the World Hepatitis Day campaign. Participants were screened for hepatitis B surface antigen (HBsAg) using the SD Bioline HBsAg Rapid Test kit. Individuals who tested positive were referred for further clinical evaluation, while those who tested negative were enrolled for vaccination using a three-dose schedule at 0, 1, and 6 months. Demographic characteristics and travel distance to NIMR were collected and analyzed using descriptive and inferential statistics, and variables significant at the bivariate level were entered into multivariate logistic regression. Result Over the 10-year study period (2015–2025), the overall HBsAg prevalence was 9.21% among 2,824 individuals tested. In the baseline 2015 cohort, 553 participants were screened, revealing a 9.0% ( n = 50) positivity rate and leaving 503 individuals eligible for immunization. Of these, 402 (80.0%) consented to participate and received the first vaccine dose. While Dose 2 completion was high at 85.6%, final Dose 3 completion dropped to 67.4% among tracked participants ( n = 344), representing 57.7% of the total enrolled cohort and yielding a 42.3% loss to follow-up rate. Notably, living near the vaccination center was significantly associated with lower odds of series completion. Conclusion HBsAg prevalence was high, while vaccination completion was suboptimal. Residential distance from the vaccination centre was associated with vaccine-series completion, although additional factors likely contributed to loss to follow-up. Decentralized mobile clinics and shorter vaccination schedules could reduce loss to follow-up and strengthen adult HBV immunization in Nigeria.