ABSTRACT
Objective: To assess the effectiveness of hepatitis B immunization program in a field setting in India. Design: Serological survey of retrospective cohorts of children, vaccinated or not vaccinated with hepatitis B vaccine. Setting: Rural field areas of five districts in Andhra Pradesh state, where childhood hepatitis B immunization began in 2003. Participants: Children aged 5-11 years who had received HB immunization (n=2674; 1357 boys) or not received such immunization (n=2350; 1236 boys). Main Outcome Measures: Serum HBsAg, anti-HBc and anti- HBs (quantitative) using automated enzyme-immunoassays in the year 2010. Results: Anti-HBs positivity was higher among immunized than in unimmunized children (53% vs.18%; P<0.001), and anti-HBc positivity was lower (1.1% vs 10.8%: P<0.01). HBsAg positivity was low in both the groups (0.15% and 0.17%; P=0.855). Anti- HBs positivity rate declined with increasing age. Conclusions: Administration of hepatitis B vaccine as part of Universal immunization program led to anti-HBs in a large proportion of children and a reduction in anti-HBc positivity, a marker of hepatatis B virus infection. These data provide evidence supporting efficacy of hepatitis B immunization program in an Indian field setting, justifying the decision to include it in the universal immunization program.