浙江省宁波市某区2010--2012年水痘突发疫情中疫苗保护效果分析

目的了解水痘疫苗接种在水痘突发疫情中的保护效果。方法收集宁波市某区2010--2012年水痘疫情报告信息，计算接种疫苗与否水痘发病率的比值比（OR），疫苗保护率及疫苗的效果指数。随机抽取未出现疫情的小学生109名，使用ELISA法进行水痘IgG抗体检测，评价疫苗接种的效果。结果该区2010—2012年共发生3起一般水痘突发事件，共报告病例40例（无死亡病例），均为幼托儿童和小学生。疫情发生所在班级学生161人，接种疫苗和未接种疫苗者发病率比较差异有统计学意义（19．42％：59．09％，X2=16．01，P〈0．01），DR值为0．17（95％CI：0．07~0．43）。疫苗总体保护率为67．13％，疫苗效果指数为3．05。未出现疫情的109名学生中，有77人接种过疫苗，但水痘IgG抗体检测显示，仅40．26％（31／77）抗体阳性。结论幼托儿童、小学生接种水痘疫苗可有效降低水痘的发病率，水痘疫苗的质量及实际保护效果需进一步评估。

Analysis on the protective effects of varicella vaccination in varicella emergency in a district of Ningbo in Zhejiang province from 2010-2012

Objective To understand the protective effects of varicella vaccination among the students in varicella emergency.Methods The varicella epidemic reporting information of a certain district of Ningbo from 2010 to 2012 were collected, and the morbidity in children with varicella vaccine inoculation or not were compared, the protective rate and the vaccine efficacy index of vaccines were calculated.The antibody of varicella were detected by ELISA in 109 students from schools without varicella emergency. Results There were 3 varicella outbreaks involving 40 cases （without death） occurred in primary schools and kindergartens in the District during 2010 to 2012.The incidence rate of vaccinated and unvaccinated children were significant difference （19.42%： 59.09%,A~=16.01, P〈0.01）, the OR was 0.17 （95%C1：0.07-0.43）. The overall vaccine protection rate was 67.13%, vaccine effectiveness index was 3.05. Seventy-seven of 109 students who didn＇ t infect were vaccinated, but results of ELISA showed that the IgG positive rate was only 40.26% （31/77）. Conclusions The varicella vaccination could protect against varicella effectively among students in kindergardens,primary schools. The quality and the actual effectiveness of varicella vaccine should be evaluated again.