Evaluation on booster immunization efficacy of hepatitis A and B combined vaccine of one dosage in children

Objective To analyze the efficacy of booster immunization with domestic Hepatitis A and B Vaccine of One dosage in children,in order to provide evidence for establishing immunization strategy.Methods A total of 1387 children aged over 5 years were selected,who had been finished the basic immunization of hepatitis B vaccine in age under 1 year,blood plasma specimens of all sampled children were detected for hepatitis B virus(HBV) surface antigen(HBsAg),antibodies to hepatitis B virus surface antigen(Anti-HBs),antibodies to hepatitis B virus core antigen(Anti-HBc) and antibodies to hepatitis A virus(Anti-HAV) by chemiluminescence.Then,they were immunized one dosage of Hepatitis A and B Vaccine(HepA and B).Their blood samples were collected after 1 month,and detected for Anti-HBs and Anti-HAV.Results The anti-HBs positive rates were 49.32%、93.58% respectively of pre-immunization,post-immunization with one dosage.The anti-HAV positive rates were 63.52%、93.08% respectively of pre-immunization,post-immunization with one dosage.There were statistical significant difference between any two rates of pre-immunization and post-immunization(P0.05).The Anti-HBs and Anti-HAV positive conversion rate of post-immunization with one dosage were 87.34% and 81.03% respectively.After immunization with one dosage,the aged rates of Anti-HBs and Anti-HAV positive conversion were dropping with growth of age(P0.05).The average Geometric means of titer(GMT) Anti-HBs and Anti-HAV negative of children immunized with one dosage HepA and B were 1326.97mIu/ml and 11.11mIu/ml respectively.Conclusions It will be suitable to useHepA and B for younger children with one dosage booster immunization,and for older children with more than one dosage booster immunization.