Anti-HBs response after hepatitis B vaccination in Expanded Program on Immunization (EPI)

After integrating hepatitis B vaccine produced by National Institute of Hygiene and Epidemiology into the Expanded Program on Immunization (EPI), seropositive rate and geometric mean titre of anti-HBs of 12-24 month old children were 69% and 157 mIU/ml in urban group, respectively. The results were higher than rural group (48.6% and 107.2 mIU/ml, respectively). Seroprotective rate increased from 48.7% to 80.2% after booster dose. This rate was highest (93.3%) in children received the booster dose 8-10 months after primary immunization. In the different time of booster dose, level of anti-HBs of 12-24 month old was higher than before