甲型肝炎减毒活疫苗加强免疫效果的初步研究

Primary study on immunologic effect of live attenuated hepatitis A vaccine (H 2 strain) after booster dose

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 。

Objective To study the immunologic effect of live attenuated hepatitis A vaccine (H 2 Strain, 10 7.0 TCID 50 ) after booster and to compare with the results of 1 dose live attenuated hepatitis A vaccine (H 2 Strain, 10 7.0 TCID 50 ). Methods 42 susceptibles with negative anti-HAV were selected in Zhengding,Hebei province. Each subject received 3 doses live attenuated hepatitis A vaccine at 0,2,6 months and was bled at 1,2,6,7,9,12 months after vaccination. Results The seroconversion rate at 1 month after the first dose was 81.4% and reached 100% after the second dose. GMT arrived the peak 2 739 mIU/ml at one month after the third dose, before stared declining. The seroconversion rate kept 100% at 12 months after the first dose, but GMT decreased to 979 mIU/ml. Conclusion The first dose worked as the base of boostering. A booster dose of live attenuated hepatitis A vaccine could induce secondary immune response well. The immunologic effect after booster dose could match the effect with inactivated vaccine and was better than the results of 1 dose live attenuated hepatitis A vaccine. The program seemed to be useful to the protective effect and the immuno-persistence.