免疫后时间及流行强度对1剂次水痘疫苗效力的影响

Effect of time after vaccination and varicella attack rate on effectiveness of a single dose of varicella vaccine

目的 探讨免疫后时间及流行强度对接种1剂水痘疫苗效力的影响。方法 对广州市天河区2011年1～6月发病的1～15岁水痘病例,采用1︰1配对的病例对照研究方法,对不同年龄、处在不同流行强度时的1剂次水痘疫苗效力（vaccine effectiveness）进行分析,并评价两者对疫苗效力的影响。结果 调查601病例/对照对子,总的疫苗效力为70.33%（95%CI：60.42%～77.76%,P〈0.01）,1岁组疫苗效力为90%（95%CI：65.27%～97.12%,P〈0.01）,随年龄增长,疫苗效力呈下降趋势（字圆趋势=12.68,P〈0.01）,逸10岁组病例与对照暴露率差异无统计学意义（P跃0.05）,疫苗基本失去保护效力。集体单位2～15岁病例511对子疫苗效力为66.67%（95%CI：54.52%～75.57%,P〈0.01）,水痘罹患率越高,疫苗效力越低,罹患率在15%以上时,疫苗效力差异无统计学意义（P跃0.05）,疫苗基本失去保护效力。结论 接种1剂水痘疫苗约10%初次免疫失败;免疫后时间及流行强度对疫苗效力均有明显影响,后者影响更大。若将1剂免疫程序改为2剂免疫程序,对控制儿童水痘暴发将具有重要意义。

Objective To investigate the effect of time after vaccination and varicella attack rate on the effectiveness of a single dose of varicella vaccine. Methods A case-control study with 1 ： 1 matching was performed in patients at ages of 1 - 15 years, who occurred in January to June 2011 in Tianhe District, Guangzhou City, China, to evaluate the effect of time after vaccination and varicella attack rate on the effectiveness of a single dose of varicella vaccine. Results A total of 601 pairs of patients/normal controls were investigated. The total effectiveness of vaccine was 70. 33%（95% Ch 60. 42% ~ 77.76%, P 〈 0. 01 ）. The effectiveness of vaccine was 90%（95% CI： 65.27% - 97. 12%, P 〈 0. 0h ） in the children at ages of one year, and showed a decreasing tendency with increasing age （）~ ~,d = 12. 68, P 〈 0. 01 ）. The varicella attack rates showed no significant difference in the patients/normal controls at ages of not less than 10 years, indicating basic disappearance of protective effect of vaccine. In the 511 pairs of patients / normal controls at ages of 2 15 years in cluster case study, the effectiveness of varicella vaccine was 66. 67%（95% Ch 54. 52% - 75. 57%, P 〈 0. 01 ）, and decreased with the increasing attack rate, which showed no significant difference in patients and in norlnal controls when the attach rate was more than 15%（P 〉 0. 05）, indicating basic disappearance of protective effect of vac- cine. Conclusion The failure rate of vaccination with a single dose of varicella vaccine was about 10%. Both the time af- ter vaccination and varicella attack rate showed significant effect on the effectiveness of varicella vaccine, while the latter was more likely. It was suggested that a booster dose of varicella vaccine should be given to control the outbreak of vari- celia in children.