浙江省衢州市儿童接种1剂次水痘减毒活疫苗的免疫效果

Effectiveness of One-dose Varicella Vaccine among Children in Quzhou City of Zhejiang Province

目的分析浙江省衢州市适龄儿童接种1剂水痘减毒活疫苗（VarV）的免疫效果,为制定水痘防控策略提供依据。方法收集疾病监测信息报告管理系统中报告的2005～2012年出生儿童的水痘病例,运用浙江省免疫规划信息系统查找VarV接种信息,计算VarV保护效果（VE）。结果衢州市2005～2012年出生儿童报告水痘病例1 226例,其中突破病例323例,突破病例的平均发病年龄晚于无VarV免疫史的病例,幼托儿童和学生是水痘突破病例的高发人群。衢州市VarV接种率呈逐年上升趋势,VarV接种率与水痘发病率之间呈负相关。2005年出生儿童在1～2岁接种1剂VarV的估算总VE为69.5%（95%CI：61.2%～76.0%）,接种后≤3年、4～5年和≥6年的VE分别为96.5%（95%CI：93.4%～98.1%）、87.7%（95%CI：82.4%～91.4%）、84.1%（95%CI：78.1%～88.5%）。结论接种1剂VarV不能有效避免突破病例,且VE随时间而下降;建议实施2剂次VarV免疫程序。

Objective To determine the effectiveness of one dose of varicella vaccine（ VarV） among eligible children in Quzhou,Zhejiang province,and to provide evidence for varicella prevention strategies.Methods Varicella incidence and VarV vaccination data of children born in 2005-2012 were collected from the National Notifiable Disease Reporting System and the Zhejiang Provincial Immunization Program Information Management System and used to determine vaccine efficacy（ VE）. Results 1 226 varicella cases,including 323 break-through varicella cases,were reported in children born in 2005-2012. Children with break-through varicella were older than unvaccinated children getting varicella. Preschool children and students were high-risk populations for break-through infection. The VarV coverage rate in Quzhou increased year by year. There was a negative correlation between the incidence rate of varicella and VarV coverage rates. The total estimated VE of one dose of VarV given at 1-2 years of age among children born in 2005 was 84. 6%,and VEs for ≤3,4-5,and ≥6 years after vaccination were 96. 5%（ 95% CI： 93. 4%-98. 1%）,87. 7%（ 95% CI： 82. 4%-91. 4%） and 84. 1%（ 95% CI： 78. 1%-88. 5%）,respectively. Conclusions One dose of VarV could not effectively avoid break-through cases,and its VE decreased with time. We recommend a two-dose VarV immunization strategy.