目的　观察甲型肝炎 (甲肝 )减毒活疫菌 (10 7.0 TCID50 )加强免疫效果 ,并同活疫苗一针法结果进行比较。方法　在河北省正定县选择 42名经事先检测甲肝抗体阴性的易感儿童 ,分别于0、2和 6个月各接种一剂甲肝减毒活疫苗 ,并于接种后 1、2、6、7、9和 12个月采集血清标本 ,观察免后抗体动态变化。结果　第 1剂接种后 1个月抗体阳转率达 81.4% ,第 2剂免后抗体阳转率达 10 0 % ,抗体水平于第 3剂免后 1个月达高峰 ,为 2 739mIU/ml,以后呈下降趋势 ,免后 12个月抗体阳转率仍为 10 0 % ,抗体水平下降至 979mIU/ml。结论　甲型肝炎减毒活疫苗加强免疫能诱导良好的免疫回忆反应 ,其免疫学效果同史克灭活疫苗相当 ,而明显高于活疫苗一针法。活疫苗加强免疫中 ,初免是基础。活疫苗加强免疫会提高疫苗保护效果 ,并延长疫苗的免疫持久性 Objective To observe the effect of enhancing the immune effect of attenuated Hepatitis A (Hepatitis A) attenuated live bacteria (10 7.0 TCID50) and compare the results with the live vaccine. Methods Forty-two susceptible children who were negative for hepatitis A antibody were selected in Zhengding County, Hebei Province. One live attenuated attenuated hepatitis A vaccine was given at 0, 2 and 6 months respectively. After inoculation, 1,2,6,7 Serum samples were collected at 9 and 12 months to observe the dynamic changes of antibody after immunization. Results The antibody positive rate reached 81.4% at 1 month after inoculation of the first dose and 10 0% after the second dose. The antibody level peaked at 1 month after the third dose was 2739 mIU / ml , Followed by a downward trend. After 12 months, the antibody positive rate was still 100% and the antibody level dropped to 979mIU / ml. Conclusion Hepatitis A attenuated live attenuated vaccine can enhance the immunological reaction induced by immunization. The immunological effect is comparable to that of the Shigella live vaccine, but significantly higher than that of the live vaccine. Live vaccine to enhance immunity, the initial release is the foundation. Boosting live vaccines boosts vaccine protection and prolongs vaccine immunity