Pre-S_2抗原在乙肝疫苗中的免疫作用的探讨

STUDY ON THE EFFECT OF PRE-S2 IN HBV VACCINE FOR ITS US EFULNESS

比较三种乙型肝炎血源疫苗和一种重组DNA(r-DNA)疫苗诱导Pre-S_2抗体阳性率与阻断乙型肝炎病毒母婴传播的有效率,其中rDNA疫苗不含有Pre-S_2蛋白,免疫后不产生Pre-S_2抗体,加热灭活疫苗按3μg与6μg两种剂量免疫后,半数以上对象均可产生Pre-S_2抗体,甲醛一步法灭活疫苗免疫后有30％婴儿产生Pre-S_2抗体。阻断母婴传播的有效率分别为:rDNA疫苗72.2％,甲醛一步法灭活疫苗70.1％,加热灭活疫苗3μg组35.6％,6μg组71.9％。疫苗免疫效果同HBsAg含量有关,似同Pre-S_2蛋白关系不明显。免疫后抗HBs阳性率与反映抗HBs含量的S/N值均同Pre-S_2抗体阳性率没有明显联系。Pre-S_2蛋白似非决定乙肝疫苗有效率的主要成分,而疫苗中的S蛋白含量对疫苗的免疫效果起十分重要作用。

Four groups of infants from HBV carrier mothers were vaccinated with different HBV vaccines (1.3μg doses, flash-heating inactivated. 2. 6μg doses. 3. 20μg doses, formalin inactivated. 4.8μg doses of recombinant hepatitis B vaccine.)at birth,one and six months. Only the last vaccine did not contain the protein Prc-S2. The protective effecacy in infants at 12 months of age was 35.6% in the 3μg group, 71.3% in the 6μg group, 70.1% in the 20μg of formalin inactivated group and 72.2% for recombinant HBV vaccine.These results indicated that HBV vaccines could offer high post exposure protection when used in high doses.But the protein pre-S2 did not play an important role in this study .The mechanism of the protection offered by HBV vaccine needs further investigation.