Post-Vaccine Immunity against Hepatitis B in Burkina Faso children

Introduction: Hepatitis B is a major public health problem in the world. The routine immunization of infants against this disease has been effective in Burkina Faso for about ten years. The purpose of this study was to evaluate immunity against HBV in vaccinated children after a decade of vaccination. Methods: a descriptive cross-sectional study was conducted; it included all children who had received at least one dose of HBV vaccine. A child was fully vaccinated if he had received all three doses of the vaccine. Assays for hepatitis B surface antigen (HBsAg) rates and anti-HBs antibody (anti-HBs) have been performed with the PLC ARCHITECT 4100. The latter threshold 10 IU/L for the title of anti-HBs antibody was considered to define a “good immunization”. Logistic regression was used to determine the factors influencing the degree of immunization. Results: 198 children were included with a sex ratio of 1.2. Low birth weight was found in 10.40% of them. More than 30% of children received their first dose of vaccine between three and five months. Fully vaccinated children accounted for 89.4%. The overall prevalence of HBsAg was 1% and that of the anti-HBs, 79.8%. Eight out of ten children vaccinated were protected. The mean titer of the anti-HBs was 254,5/L ± 329.1UI. A multivariate analysis showed that only age (and thus decline compared to vaccination) was a factor significantly associated with optimal post-vaccination protection against hepatitis B (p = 0.011). Conclusion: This study showed that the majority of children acquire protective anti-HBV immunity after primary vaccination according to the national immunization (Expanded Program of Immunization: EPI) regimen. However, the considerable decrease in the rate of anti-HBs after 3 years should perhaps be discussing the relevance of a booster vaccination within the epidemiological context and other risk factors. Keywords: HBV vaccination; Immunization; EPI-Burkina Faso; childre