水痘疫苗保护效果的病例对照分析

Effectiveness of varicella vaccine：a case-control study

目的：分析接种1剂次水痘减毒活疫苗对儿童的保护效果。方法采用1∶2匹配病例对照研究方法,对上海市浦东新区2015年5月—2016年4月期间12岁以下的127例水痘病例和254例对照的基本情况、疫苗接种情况、临床症状等进行问卷调查,统计分析水痘疫苗保护效果。结果病例组1剂水痘疫苗接种率（83.46%）低于对照组（90.55%）,差异有统计学意义（χ^2=4.08,P〈0.05）；1剂水痘疫苗接种后保护率为64.29%（95%CI为42.00%-78.00%）。突破病例均有1剂水痘疫苗接种史,占总病例数的83.46%。原发病例较突破病例的临床症状严重,突破病例的接种时间越长,其临床症状就越严重。结论接种水痘疫苗是预防水痘发生的有效措施,但接种1剂水痘疫苗保护效果有限,建议及时推行水痘疫苗两针法。

Objective To evaluate the vaccine effectiveness （ VE） in children who received one dose of live attenuated varicella vaccine. Methods A questionnaire-based 1 ∶ 2 matching case-control study was conducted during May, 2015 to April, 2016 to evaluate the VE based upon the demographic data, vacci-nation status and clinical symptoms of 127 children with varicella and 254 healthy subjects under 12 years old. Results Compared with the healthy subjects, 83. 46% of the patients with varicella were immunized with one dose of varicella vaccine, which was lower than that of the control group （90. 55%） （χ^2=4. 08, P〈0. 05）. The overall protective rate of one dose of varicella vaccine reached 64. 29% （95% CI：42. 00%-78. 00%）. Of the 127 cases of varicella, 83. 46% were breakthrough cases immunized with one dose of var-icella vaccine. Primary cases presented more severe clinical symptoms than breakthrough cases. The longer the interval between vaccination and varicella-zoster virus infection was, the more severe the breakthrough cases would be. Conclusion Varicella vaccine is effective for preventing varicella, but the VE of one dose of varicella vaccine is limited. A two-dose varicella vaccination strategy should be proposed in our country as soon as possible.