Immunogenic effect of hepatitis B vaccine in children: Comparison of two-and three-dose protocols

The immunogenic effect of hepatitis B vaccine was evaluated in 183 seronegative infants from Senegal. Seventy‐two seronegative infants received two 5‐μg doses of vaccine at a two‐month interval and 111 seronegative infants received three 5‐μg doses at one—month intervals. All the children had a booster dose one year after the first injection of vaccine. No difference between the two groups was observed in the seroconversion rate (93.1% and 94.6%, respectively); in the proportion of high anti—HBs titer; or in the anti—HBs geometric mean titer (82 and 92 mIU/ml, respectively). These results demonstrate that two doses of 5μg of hepatitis B vaccine are sufficient in infants to obtain a high immunogenic effect.