云南省2011～2015年口服脊髓灰质炎减毒活疫苗补充免疫活动分析

Analysis of Supplementary Immunization Activities of Oral Poliomyelitis Attenuated Live Vaccine in Yunnan Province,2011-2015

目的对云南省2011～2015年口服脊髓灰质炎（脊灰）减毒活疫苗（Oral Poliomyelitis Attenuated Live Vaccine,OPV）补充免疫活动（Supplementary Immunization Activities,SIA）进行分析,为维持和巩固无脊灰免疫策略的调整提供参考。方法收集云南省2011～2015年OPV SIA报表和督导评估资料,进行描述性分析。结果在脊灰野病毒（Wild Poliovirus,WPV）输入与传播风险评估的基础上,云南省2011～2015年共在全省范围内开展了6轮OPV SIA,共接种18 539 740剂OPV,每1轮OPV SIA国内儿童和外籍入境儿童报告接种率均〉95%。共发现＂0剂次＂免疫儿童226 027人,占报告应种总数的1.20%;入境外籍儿童和国内儿童＂0＂剂次比例分别为11.80%、1.03%（χ2=78 180.97,P=0.00）,其中1～6岁入境外籍儿童和国内儿童＂0＂剂次的比例分别为92.66%、17.29%（χ2=32 363.69,P=0.00）。6轮OPV SIA共对189个县次开展了接种率快速评估,平均评估接种率为98.05%,有16个县次评估接种率〈95%。结论云南省SIA运转模式成熟,最大限度填补了国内儿童和入境外籍儿童的免疫空白,有效防止了脊灰野病毒与脊灰疫苗衍生病毒（Vaccine Deprived Poliovirus,VDPV）的输入和VDPV循环的发生。

Objective To evaluate the implementation of supplementary immunization activities（ SIAs）of oral poliomyelitis attenuated live vaccine（ OPV） in Yunnan,2011-2015,and to provide evidence for adjusting immunization strategies to maintain the polio-free status. Methods Immunization data during OPV SIAs were reported from local staff and collected during supervision and assessment activities. Descriptive epidemiological methods were used to analyze the data. Results Based on risk assessments of wild poliovirus importation and transmission,6 rounds of OPV SIAs were conducted from 2011 to 2015 in129 counties of Yunnan. A total of 18 539 740 doses of OPV were administered during the SIAs. The coverage rate of OPV in each round reached above 95% among local children and among immigrant children from Myanmar. During the SIAs,226 027（ 1. 20%） children who previously had received zero doses of OPV were found; 11. 80% of immigrant children and 1. 03% of local children had received zero doses（ χ2= 78 180. 97,P = 0. 00）; 92. 66% of 1-6 year old immigrant children and 17. 29% of 1-6 year old local children were zero-dose children（ χ2= 32 363. 70,P = 0. 00）. Rapid assessments during 6rounds of SIAs showed that the average coverage of OPV was 98. 05% in 189 counties / occasions,with a coverage of less than 95% in 16 counties / occasions. Conclusions OPV SIAs were implemented well in Yunnan; SIAs vaccinated local and immigrant children who previously had received zero-doses of OPV,and the SIAs may have interrupted the importation of wild poliovirus or vaccine-derived poliovirus（ VDPV） and prevented circulation of VDPVs.