应用青岛市6-13岁人群病例对照研究评价水痘减毒活疫苗保护效果

Varicella vaccine effectiveness:a case-control study among 6-13-year-olds in Qingdao city

目的评价青岛市儿童水痘减毒活疫苗(Varicella attenuated live vaccine,VarV)的保护效果(Vaccine effectiveness,VE)。方法采用病例对照研究设计,选择青岛市14所学校48个班级的6-13岁学生,将2013-2018年有、无水痘发病史的学生分别纳入病例组、对照组,收集水痘发病和VarV接种信息,计算VarV的VE。结果本研究纳入532例水痘病例和1 596例对照。VarV的总体VE为51.7%(95%CI:40.9%-60.6%);接种1剂次、2剂次VarV的VE分别为44.4%(95%CI:31.5%-54.8%)、81.8%(95%CI:71.0%-88.6%)。在接种1剂次VarV后0-2、3-4、5-6、7-8、≥9年的VE分别为90.1%、64.8%、50.2%、40.8%、34.5%。结论儿童接种1剂次VarV的保护效果较差,且随着接种后时间的推移而递减;建议适龄儿童接种2剂次VarV,并纳入国家免疫规划。

Objective To evaluate the effectiveness of varicella vaccine(VarV) among children in Qingdao city.Methods We used a case-control study design to select 6-13-year-old students from 48 classes of 14 schools in Qingdao, and divided the students into a case group and a control group according to their varicella illness history during 2013-2018. We used varicella illness data and VarV vaccination data to measure varicella vaccine effectiveness(VE).Results We included 532 varicella cases and 1 596 controls. Overall VE was 51.7%(95%CI: 40.9%-60.6%). VEs for one dose and two doses of VarV were 44.4%(95%CI: 31.5%-54.8%) and 81.8%(95%CI: 71.0%-88.6%). VEs for 0-2, 3-4, 5-6, 7-8, and ≥9 years after one dose of VarV were 90.1%, 64.8%, 50.2%, 40.8%, and 34.5%.Conclusions The effectiveness of one dose of VarV was low in children, and effectiveness decreased with increasing time since vaccination. We recommend introducing a two-dose VarV schedule for children into the National Immunization Program.