Level of Antibody Response against Hepatitis B Virus after Vaccination and Seroprevalence of HBV in Children Addis Ababa, Ethiopia

Approximately 2 billion people worldwide are infected with HBV and more than 240 million are chronic carriers. The World Health Organization officially launched the introduction of the hepatitis B vaccine for children in 1980. Since then, different countries have determined the level of response to the vaccine. Since the introduction of the vaccine in Ethiopia in 2007, there have been few studies evaluating the antibody response to the HBV vaccine. Therefore, the purpose of this study is to determine the HBV antibody response after hepatitis B vaccination and to evaluate the HBV seroprevalence of children in Addis Ababa, Ethiopia. A cross-sectional study was conducted using a multistage probability sampling technique. Four hundred and fifty children between the ages of five and eight living in Addis Ababa were enrolled. Socio-demographic characteristics were obtained through a structured questionnaire and three to four ml of blood was collected from each child. ELISA was performed to determine antibody levels against HBV. The average age is seven + one (SD) years. Anti-HBs were detected in 54.3% (208/450) of children, and girls 98 (54.7%) had a slightly higher level of protection than boys 110 did (53.9%). The overall coverage rate of the vaccine in this study was 85.1%. The proportion of children with protective levels (> 10 mIU / ml of anti-HBs antibodies) decreased with increasing age of the children: 5, 6, 7 and 8 years were 52.6%, 60%, 43.5% and 37.1%, respectively. The seroprevalence rate for HBsAg is 0.4% and the seroprevalence rate for anti-HBc is 5.6%. Age and antibody response level were negatively correlated (p = 0.001), while gender and history of HBV infection were not significantly correlated. Age was also significantly correlated with anti-HBc seropositivity (p = 0.003). HBV vaccine coverage for children is high, but the antibody response to the vaccine appears to be low. The seropositivity rate for the virus is also very low. Low levels of response to the vaccine should be a problem. For unresponsive children, revaccination or booster doses should be considered. More research needs to be done