The Immunization Effects Of5～16Years Old Children At One Year Post-hepatitis B Vaccine Booster Vaccination

Objectives1. Testing the antibody to Hepatitis B virus surface antigen (anti-HBs) of5~16years oldchildren who complete the immune booster of three doses Hepatitis B vaccine after oneyear,;analyzing the immune factors of one year post-booster on5~16years old children.2. The follow-up observation of anti-HBs titers at1month post-one dose boostervaccination,1month post-three doses booster vaccination and1year post-three doses boostervaccination is to evaluate of immune effects and its influencing factors, to provide evidence andstrategy for the hepatitis b vaccine booster immunization.MethodsResearch samples were selected from3cities (6counties) in Zhejiang Province accordingto local levels of Hepatitis B virus (HBV) endemicity. Two towns were then selected from eachof the six counties as research field. The children in local schools aged5to16, who receivedthree doses booster vaccination during one year ago and completed to collect blood samples at1month post-one dose booster vaccination,1month post-three doses booster vaccination and1year post-three doses booster vaccination, were selected as the study subjets of follow-up studyat one year post-booster. After imformation and booking,2mL of venous blood was collectedfrom each of these children to test anti-HBs titers. Finally, via chemical luminescence method,all serological indicators went through quantitative detection. All data was input twicely by EPIdata3.2software, and was then analyzed by Excel2010software and SAS9.2software.Results1. Immunization effects of5~16years children at one year post-booster.In the study, a total of2419children completed booster vaccination of three dosesHepatitis B vaccine after5~16years post-primary vaccination were investigated and collectedblood samples,then they were checked anti-HBs. A total anti-HBs positive rate of those chilrenwas91.90%. And the anti-HBs positive rate in male was91.85%, the anti-HBs positive rate infemale was91.95%. There was no statistically significant difference of anti-HBs positive ratebetween male and female (P>0.05). The anti-HBs positive rate in Areas of low, intermediateand high HBV endemicity were91.14%,93.06%,91.89%, and there were no statisticallysignificant differences of the anti-HBs positive rates among those areas (P>0.05). At1yearpost-booster vaccintion, Geometric Mean Titer (GMT) of anti-HBs of those children was92.83 mIU/mL. After being stratified by gender, the GMTs were no statistically significant differences,and it was the same with the results of GMTs were stratified by different HBVendemic areas.The children in different HBV endemic areas were further stratified by gender or age, but thepositive rate and GMT of anti-HBs were not statistically significant different.At1year after booster, the anti-HBs positive rate the children aged13~16years was86.39%, much lower than5~12years old group (P<0.05), the children aged13~16old antibodyGMT levels were lower than other groups. The anti-HBs positive rate vaccinated withRecombinant Hepatitis B Vaccine (HPY) of those children was higher than the other threevaccines (P<0.0083). The children vaccinated with different Recombinant Hepatitis B Vaccinewere further stratified by gender, age or HBVendemic areas, the results were similar as beforestratification. And the GMTs of anti-HBs vaccinated with Recombinant Hepatitis B Vaccine(HPY) of those children were much higher than the other three vaccines.2. Immunization effects druing different periods post-booster vaccination.2419children follow-up observation of anti-HBs positive rates at1month post-one dosebooster vaccination,1month post-three doses booster vaccination and1year post-three dosesbooster vaccination were92.72%,99.75%and91.90%, respectively, and the correspondingGMTs were498.54,987.87and92.83mIU/mL, there were not statistical significance diffrernt(P<0.05). Further stratified by gender age or HBVendemic areas, the anti-HBs positive rate andGMTs trend during different periods post-booster vaccination were similar as beforestratification. From1month post-one dose booster vaccination,1month post-three dosesbooster vaccination to1year post-three doses booster vaccination, the anti-HBs positive ratevaccinated with Recombinant Hepatitis B Vaccine (HPY) of those children was higher than95%, and the GMTs was higher than three other vaccines. The anti-HBs positive rate of thechildren aged13~16years was different from other age groups which were maintained at morethan90%during different periods, were corresopnding81.01%,99.05%and86.39%andantibody GMT level is lower than other age groups.The anti-HBs titers post–booster weredeclined with the lower anti-HBs titers pre-booster((P<0.05). And there was a higher correlationbetween1month post-three doses booster and1year post-three doses booster with or withoutstratified by anti-HBs pre-booster.Conclusions1. The immunization effect after1year of all the follow-up children was good except forthe anti-HBs dropped dramatically.2. Immunization effect of Recombinant Hepatitis B Vaccine (HPY) is superior to otherthree kinds of Hepatitis B Vaccine.3. Individuals after successful primary vaccination those who to enter adolescence oradulthood preferably periods were within10~13years after the primary. 4. Three doses booster really does make low or non-responders in the short-term acquireenough protective antibody, and maintain protective antibody concentration long than one dosebooster. Therefore, we recommend three doses booster for those who anti-HBs pre-booster lessthan1mIU/mL.