Determination of Anti-HBsAg antibody titers among children under five years who received Hepatitis B vaccine under UNEPI in Kawempe Division, Kampala-Uganda

Abstract

Background: Hepatitis B Virus is a global health threat with estimated 257 million people chronically infected with the infection (WHO 2017). HBsAg sero prevalence is approximately 3.6% with high endemicity observed in African population. In Uganda, the national prevalence is 10% and the Ministry of health integrated childhood Hepatitis B vaccination on the Uganda National Extended Programme on Immunization since 2002 to reduce on high morbidity and mortality rates in the country. The prevalence of immunological non responsiveness of HBV in children under 5years have not been indicated in Uganda. Objective: The objectives of the study were to determine the levels of Hepatitis B vaccine specific anti-HBs antibodies in children under 5years of age as well as prevalence of acute, chronic and resolved HBV exposure, Obtain the prevalence of non-response to HBV Vaccine in under 5year old childhood recipients. Method: The study was cross-sectional nested in a parent study titled “Childhood responses to Hepatitis B Vaccine in Uganda; The role of Human Leukocyte Antigen (HLA) and T-cell Receptor (TCR) diversity. We aimed at using 501 archived serum samples from vaccine recipients under 5years of age at CFU Medical Centre in Kawempe division. Archived serum samples from the parent study were thawed and Combo test was performed on all for detection of antigens and Antibodies thus, HBsAg, HBeAg and HBcAb in serum prevalence of exposure of HBV infection will be obtained. Antibodies titers were performed by Roche COBAS e-411. Results: Majority of the study participants were combo HBV susceptible 65.5%, participants that had detectable Hepatitis B Antibodies and the responders were (95.9%) with moderate levels of response 48.8% and non-responders of 4.1%. Acute infection was 1.6% with lowest 0.2% chronic. Conclusion: The study revealed that 65.5% of the study participants were not vaccine protected and those with HBV vaccine protection were 95.9% that were recorded as responders.4.1% non-response rate was recorded and 1.6% of the participants had acute infection. Recommendations Public Health intervention should be done by Ministry of Health-Uganda to evaluate UNEPI Hepatitis B Vaccination programme with the essence of improving efficacy and potency of HBV Vaccine.