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.