甲型肝炎病毒活疫苗再免疫效果的研究

目的 探讨甲型肝炎减毒活疫苗加强免疫的可行性。方法 用AbbottELA改良法定性和定量检测再免疫组、初免疫组和自然感染组受试者血清中的甲型肝炎抗体，并进行对比分析。结果 再免疫后甲型肝炎抗体阳性率和几何平均滴度在2周内达高峰。再免疫组和自然感染组对活疫苗免疫反应存在差异。再免疫组初免成功抗体又转阴者，再免疫后抗体阳性率83．3％（10／12），显著高于初免疫失败者再免疫后50％的阳性率（17／34），两者又均高于初免疫者（29．6％）。结论 再免疫可引起免疫回忆反应，且初免疫成功率直接影响到再免疫的效果。Abbott ELA改良法检测血清中甲型肝炎抗体仍低估了原发性免疫反应，需用更为灵敏特异的方法检测疫苗抗体。

RESEARCH ON REIMMUNIZATION WITH LIVE ATTENUATED HEPATITIS A VACCINE

Objective To explore the feasibility of reimmunization with live attenuated hepatitis A(HA) vaccines.Methods Randomly sampled children were divided into 3 groups:reimmunization,primary immunization and natural infection.Antibodies against heptatitis A virus(anti-HAV) were detected qualitatively and quantitatively with modified Abbott enzyme immunoassay and the results were analyzed subsequently.Results The positive rate of anti-HAV and the mean geometrictiter(GMT) came to a climax within 2 weeks after reimmunization and natural infection.The positive rate of anti-HVA after reimmunization was 83.3%(10/12)in those whose antibodies were converted into negative ones after primary immunization,significantly higher than that (50%,17/34)in those whose primary immunization failed and to whom vaccinations were applied again, but both higher than that (29.6%)in the primary immunization group.Conclusion Anamnestic reactions can be induced by reimmunization, and the effect of reimmunization depends on the results of primary immunization. The primary immune reactions were underestimated in the detection of anti-HAV.A more sensitive and specific method is needed badly to detect anti-HAV after vaccinations.