【摘要】 目的观察规范化甲型肝炎减毒活疫苗ＬＡ－１株的免疫原性和抗体动态变化。方法在广西柳城县选择３１０５名经甲肝抗体检测为阴性的易感儿童，以随机双盲安慰剂对照法分成疫苗组（１６２４名）和对照组（１４８１名），疫苗滴度１０６．７５ＴＣＩＤ５０；疫苗组于免疫后３、６、１２、２４、３６月份分别进行定人和定群观察；免后３年对两组进行横断面调查甲肝抗体。结果１剂疫苗免后抗体高峰出现于３～６个月，抗体阳转率峰值达到９１．４％，ＧＭＴ为１０６．３１ｍＩＵ／ｍｌ；３年后，甲肝抗体阳性率并未随免疫后年限延长而明显下降，疫苗使接种儿童抗体阳性率达到非接种儿童的３．８倍。结论１剂国产规范化甲肝减毒活疫苗（ＬＡ－１株）可诱导高水平且较持久的免疫。更多还原

【Abstract】 Objective To evaluate the immunogenicity and the dynamic change of anti-HAVin children immuned with a standardized live attenuated hepatitis A vaccine（LA-1 strain）.Methods 3105 children of 1-9 years old with hepatitis A IgG ant ibody negative selected from Liucheng County，Guangxi Zhuang Autonomous Region were randomly divided into vaccine（1624 children）or control group（1481 children） equal in ages and sexes.Vaccine group received one single dose of HAV vac-cine of 106.75 TCID50.Blood samples were collected at 3，6，12，24 and 36 months after v accination in vaccine group and 36 months in control group and tested for anti-HAV antibody using HAVAB sup-plied by Imx kit（Abbott Lab.）.Results Seroconversio n rate and GMT arrived at the peak 6 months after vaccination，the rates of serocon version were 91.4%，88.6%，88.6% and 80.0% and GMT were 106.31，105.09，105.77 and 99.20mIU/ml at 6，12，24 and 36 months after vaccination，respectively.Three years later ，the rates of seroconversion was not decreased with years vaccination and it was 3.8 times higher in vaccine group than that in non-vaccineers.Conclusion One single dose of standardized HAV live attenuated vaccine（LA-1strain）can induce hig her level and persis-tence of antibody.更多还原