目的重组(酵母)乙型肝炎(乙肝)疫苗(YDV)已纳入儿童计划免疫,为观察其免疫效果的持久性及免疫记忆反应.方法对山西省晋中、阳泉市1995年出生,并按照免疫程序全程免疫的儿童,进行了8年的免疫持久性观察.同时在该年龄组儿童免疫5年后,对乙肝病毒表面抗体(抗-HBs)＜2.1mIU/ml者,加强免疫YDV 1针(5μg),观察其免疫反应.结果基础免疫后,抗-HBs阳性率、有效阳性率、几何平均滴度(GMT)分别达到92.08%、84.16%、29.21mIU/ml,以后逐年下降,免疫后8年时分别降低为65.63%、40.63%、5.89mIU/ml.抗-HBs阳性率下降速率较慢,年均3.78%,有效阳性率的下降速率较快,年均降低6.22%,GMT每年平均下降3.33mIU/ml,免疫后8年较1年时降低79.84%.免疫后5年抗-HBs＜2.1mIU/ml的儿童,加强免疫1针后其抗-HBs阳性率和有效阳性率均达到100%,GMT达基础免疫1年时的8.33倍.结论 YDV免疫后,机体同样产生特异性体液和细胞免疫记忆.由于YDV与血源乙肝疫苗的理化性质等方面的不同,其免疫的长期记忆和保护效果如何,需否加强免疫等问题,尚需进一步研究.
Objective Recombinant yeast-derived hepatitis B vaccine (YDV) has been incorporated into the EPI. In order to study its persistence and immunoligic memory of immune effect. Methods The children born in 1995 had been immunized with full course of YDV 8 years ago were persistent observed. The anti-HBs<2.1mIU/mL after 5 years of YDV immunization were selected and observed its immune reaction after booster immunization with 1 dose 5 μg of YDV. Results The results showed that the positive rate of anti-HBs was 92.08%,the effective positive rate was 84.16%,the mean geometric titres (GMTs) was 29.21mIU/mL after basic vaccination respectively and 8 years later was 65.63%,40.63%, and 5.89mIU/mL, respectively which means the positive rate of anti-HBs,the effective positive rate and the GMTs decreased year by year.The positive rate of anti-HBs decreased slowly,it average decreased 3.78% annually,but the effective positive rate of anti-HBs decreased more quickly that was 6.22%, the GMTs was 3.33mIU/mL which decreased 79.84% compared with 1 year immunization.The selected children whose anti-HBs<2.1mIU after 5 years immunization,the positive rate of anti-HBs and effective positive rate both reached 100% after booster 1 dose 5μg of YDV. GMT of anti-HBs was 8.33 times high than 1 year basic immunization,which showed the special body fluid and cell immunologic memory could be produced after immunization of YDV. Conclusion Due to the difference of physicochemical property between YDV and PDV,whether they have long-term immunologic menmory,protective effect and booster immunization need to be further studied.
Chinese Journal of Vaccines and Immunization