甲型肝炎灭活疫苗和冻干减毒活疫苗接种后1年的免疫原性研究

目的评价甲型肝炎灭活疫苗和冻干减毒活疫苗接种1剂1年后的免疫原性。方法采用单一中心随机双盲试验设计,对18月龄~4岁健康幼儿受试者随机接种1剂设盲的甲肝灭活疫苗或甲肝减毒活疫苗。接种前及接种后12个月,采用微粒子酶免法（MEIA）定量检测受试者甲型肝炎抗体（抗-HAV）。结果免疫后1年,甲肝灭活疫苗组和甲肝减毒疫苗组分别有124人和135人完成试验,抗-HAV阳转率分别为95.2%和91.1%,抗-HAV的几何平均浓度（GMC）分别为101.7 IU/L和65.5 IU/L,甲肝灭活疫苗免疫的抗体水平明显高于甲肝减毒活疫苗（P〈0.001）。结论接种1剂甲肝灭活疫苗或甲肝减毒活疫苗后12个月,均可产生良好的免疫效应,甲肝灭活疫苗免疫的抗体水平明显高于甲肝减毒活疫苗。

Anti-HAV immune responses in young children vaccinated with an inactivated and a live attenuated hepatitis A vaccine respectively

Objective To evaluate the anti-HAV levels of young children in one year after the vaccination with one dose of an inactivated hepatitis A vaccine and a live attenuated hepatitis A vaccine,respectively.Methods A double-blind,randomized and controlled clinical trial was conducted in 332 healthy children volunteers aged 18 months to 4 years.Participants were randomly vaccinated with a dose of an inactivated hepatitis A vaccine or a live attenuated hepatitis A vaccine.Hepatitis A antibodies were detected by the method of MEIA in the serum collected before vaccination,6 and 12 months after vaccination.Results The serum conversion rates of anti-HAV were 95.2% and 91.1% for the inactivated and attenuated vaccine respectively.The geometric mean concentration of anti-HAV was significantly higher in the children vaccinated with the inactivated vaccine（101.7 IU/L） than that in the children vaccinated with the attenuated vaccine（65.5 IU/L）（P0.001）.Conclusions The positive rates of anti-HAV were high in the children immunized with a single dose of inactivated hepatitis A vaccine or live attenuated hepatitis A vaccine.The antibody level induced by inactivated hepatitis A vaccine was significantly higher than that induced by live attenuated hepatitis A vaccine.