Evaluating the Effect of Hepatitis B Vaccination on Serological Markers in Ile-Ife, Osun State, Nigeria: A Cross-Sectional Study

Hepatitis B (HB) is a public health issue in Nigeria which the introduction of the HB vaccination through the National Programme of Immunization (NPI) in 2004 has not been able to eliminate due to various challenges. This cross-sectional study measured hepatitis B virus he(HBV) serological markers for infection and immunity among individuals of ages between 0 - 32 years which are divided to two cohorts/era namely Pre-vaccine and Vaccine era in Ile-Ife, Nigeria based on the introduction time of hepatitis B vaccine to the National Programme on Immunization in Nigeria. Venous blood samples were screened for the presence of hepatitis B surface antigen (HBsAg), hepatitis B surface antibody (HBsAb), hepatitis B envelope antigen (HBeAg), hepatitis B envelope antibody (HBeAb), and hepatitis B core antibody (HBcAb) using a rapid diagnostic kit. Among the 150 participants screened, 6 (4.0%) had HBsAg in them, with those born after the introduction of HB vaccine in 2004 having a higher prevalence of 2.6% (n = 4/150), while those born before had 1.3% (n = 2/150). Although the HB vaccination records were not sighted for any one of the participants, HBsAb detection was observed to be 1.2%, while HBeAb and HBcAb markers' prevalence were 34.0% and 16.0%, respectively. Only 1 (0.6%) of those born during the vaccine era had HBsAb, while 64 (83.12 %) of the same era had no detectable HBsAg indicating yet a high percentage of the population being susceptible to the HBV infection. This suggests the need to deliberately consider in-depth studies on the process and outcome of the hepatitis B vaccination in Ile-Ife. It is evident that HBV is widespread, possibly due to both vertical and horizontal transmission in the study area. Concerted efforts to ensure herd immunity that will culminate in the eradication of viral hepatitis in 2030 as proposed by the WHO is necessary.