Effect of hepatitis B vaccine booster immunization among anti-HBs negative children receiving basic vaccination 5-11 years ago

Objective To evaluate the effect of hepatitis B vaccines booster immunization among the anti-HBs negative children receiving basic vaccination 5-11 years ago in Zhejiang. Methods In September 2009, 4407 children aged ＞5 years were selected in Taizhou, Lishui and Quzhou in Zhejiang, all of the children completed the basic immunization of hepatitis B within the age 1 year. The blood samples were taken from them to detect HBsAg, anti-HBs and anti-HBc by chemiluminescence immunoassay. Totally 2164 children with negative Results received the booster of hepatitis B vaccine at 0, 1 and 6 months. The blood samples were taken from them one month after the first dose and the third dose to detect anti-HBs. Results The anti-HBs detections at one month after the first and the third doses indicated that the positive conversion rate of the antibodies was ＞95%. The differences on the immunization effect between the first dose and the third dose of different vaccines were statistical significant. Conclusion Great achievement has been made in hepatitis B immunization since the implementation of hepatitis B vaccination programme, but anti-HBs positive rate could decline as time goes on. It is necessary to conduct booster of hepatitis B vaccine in children aged ＞5 years.