The participants in this study were 182 children, 110 males and 72 females categorized into eight age groups from 2 -10 years of age.Serum samples from each participant were tested for the quantitative determination of anti-HBs antibody using enzyme linked immunosorbent assay (ELISA) as well as qualitative ELISA testing for HBsAg and HbcAb. The study showed that the efficacy of hepatitis B vaccine, as evidenced by presence of protective levels of HbsAb, is 88.5%.