儿童乙型肝炎疫苗加强免疫效果研究

目的　观察新生儿乙肝疫苗免疫后 ,加强免疫接种后的免疫应答的状况和特点。　方法　在乙肝疫苗试点区 ,选择新生儿乙肝血源疫苗免后 9～ 11年的儿童 170名 ,用 5 ug重组酵母乙肝疫苗进行加强免疫。　结果　加强免疫后1年 ,抗 - HBs的 GMT水平迅速升高为原来的 6～ 18倍 ,抗 - HBs阳性率也由免疫前的 6 2 .5 %～ 6 7.5 %上升至 10 0 % ;后随着加强免疫时间的延长 ,抗 - HBs的 GMT水平和阳性率逐渐下降 ,至免后 3年 ,1针加强组抗 - HBs阳性率降至 71.2 % ,2针加强组降至 79.2 % ,而 3针加强组仅降至 92 .5 %。　结论　国产乙肝备源疫苗具有持久的预防保护效果 ,以及良好的免疫回忆反应 ;加强免疫的效果与加强针次和加强免疫前的免疫状况有密切的关系。

Study of Immune Efficacy on Booster of Hepatitis B Vaccine among Children

Objective To observe Long-term protection efficacy among the infants who has been immunied with plasma-derived hepatitis B vaccine,and immune response after booster inoculation. Methods The 170 children,inoculated hepatitis B vaccine at birth,were boost with Yeast Recombinant Hepatitis B Vaccine(YRV). Result The results showed the anti-HBs positive rate and the geometric mean titer(GMT) gradually decreased with the lapse of time. About 55% of newborn'anti-HBs titer was less than the protective titer(<10mIu/ml).but there were no difference in the HBsAg positive rate between fifteenth year and first year after vaccination.After one year of booster with YRV.The anti-HBs positive rate has been risen to 100%,and GMT has been rapid ascended too. Conclusion The efficacy of hepatitis B vaccine was long-term.The immune reponse was obvious existed.The effect concern with booster frequency and immune conditione of children before booster.