接种3剂甲肝减毒活疫苗8年的免疫学效果

目的 观察接种3剂甲肝减毒活疫苗8年抗体持久性,并与1针法进行了比较.方法 对农村1～7岁HAV易感儿童110人,接种1剂甲型肝炎减毒活疫苗作为B组,选其中一个自然村的42名易感儿童作为A组,按0、2、6个月程序接种3剂疫苗,分别于免疫后1、2、6 7 8、12、24、36和96个月采集血清标本,检测抗-HAV总抗体.结果 B组接种甲肝减毒活疫苗后2～3个月,抗-HAV阳转率和几何平均浓度(GMC)达到高峰,分别为92.2%和126.2 mIU/ml,然后开始随时间下降.与之相比,按照0、2、6个月程序免疫的A组,抗体阳转率在第二针后即达100%,第三针后GMC达高峰,为2739 mIU/ml,A组的近期免疫效果甚至优于灭活疫苗;36～96个月B组的抗-HAV阳转率和GMC分别为75%～71%和80～89 mIU/ml;与之相比,A组36～96个月的抗-HAV阳转率和GMC分别为100%和918.2～480.6 mIU/ml,显著高于B组.结论 接种3剂甲肝减毒活疫苗近期、远期免疫效果均高于一针法,三针法加强免疫取得了良好的免疫学效果,抗体持久性和预防效果有待于进一步观察.

The immunological effects of three doses of a live attenuated hepatitis A vaccine (H2 strain) in 8 years

Objective To observe the immunohigical effects of three doses of H2 strain live attenuated hepatitis A vaccine 8 years after the administration and to compare with that of one dose of the vaccine. Methods In a country area, 110 children of 1 to 7 years old susceptible to HAV were screened and administered with one dose of the vaccine, as group B ; Group A were 42 children from one of the villages and administered with 3 doses of the vaccine according to 0, 2, 6 month schedule. Blood samples were taken for the children 1, 2, 6, 7, 8,12, 24, 36 and 96 months after the administrations respectively and detected for anti-HAV antibody. Results For group B, the sero conversion rate of anti-HAV and GMC reached peak at 92.2% and 126.2 mIU/ml respectively,and then, began to drop with time; For group A, after 2 dose of the vaccine, the sero-conversion rate reached 100%, and the GMC reached peak of 2 739 mIU/ml one month after the third dose at 7 months. So that, group A has a better short-term immunological effects than that of group B. During 36 through 96 months, the anti-HAV positive rate in group B was 75%-71% and 80-89 mIU/ml respectively, and comparatively in group A were 100% and 918.2-480.6 mIU/ml respectively. The differences between group A and B were significantly important. Conclusion A 3-dose schedule administration of H2 strain live attenuated hepatitis .A vaccine has better immunological effects than 1-dose schedule in 8years and further observations are needed.