Study on Immunization Effectiveness of Hepatitis B Vaccine in Newborns During the Period of 20 Years

Objective To understand the anti-HBs transformation tendency and the long-term protective effect in children immunized with hepatitis B vaccine at birth.Methods Totally 6,203 children,who were vaccinated with hepatitis B vaccine at birth were investigated and followed up at least once in each 2～3 years since 1986.Serum HBsAg,anti-HBs,and anti-HBc were tested.Results The results showed that HBsAg positive rate in vaccination group were 0.63%～2.94% during 20 years.The HBsAg average positive rate was 1.51% and that was significantly lower than 10.56% of same age population of background survey.The protective rate was 85.62%(95% CI:84%～86.57%).The highest peak of the anti-HBs positive rate appeared in 7th～12th months and then gradually decreased with the lapse of time.But the anti-HBs positive rate of 20-year-old children was 28.16%(mIu/ml≥10.0).The HBsAg positive rate and the anti-HBs positive rate were not changed.Conclusions The efficacy of domestic hepatitis B vaccine was long-term.The decrease of anti-HBs positive rate did not lead to increase of HBsAg positive rate.The results indicate that anti-HBs is an indicator only,at the time of booster dose is selected.