Xu Jiawei, Kuang Shanshan, Rong Rong, Zhang Yuanyuan, Tang Wenge, Wang Qing
Department of Immunization Program, Chongqing Center for Disease Control and Prevention, Chongqing, China.
Medicine (Baltimore). 2020 Jul 31;99(31):e21298. doi: 10.1097/MD.0000000000021298.
Serums were collected from people to assess whether polio immunity level was high enough to satisfy the polio vaccine immunization switch in Chongqing.People in 7 age groups (<1 year, 1-2 years, 3-4 years, 5-6 years, 7-14 years, 15-19 years, ≧20 years) were randomly selected in 3 areas by different geographical features in 2015. Peripheral venous blood samples were obtained and assays to detect poliovirus (PV) -neutralizing antibodies were performed. Acute flaccid paralysis (AFP) data was collected from 2012 to 2016 in Chongqing to evaluate the performance of AFP surveillance system by indicator analysis.A total of 636 people were tested for PV neutralization antibodies (NA). Overall NA seroprevalence for PV1, PV2 and PV3 were 93.40%, 96.38% and 91.82%, and geometric mean titers (GMTs) were 61.14, 66.78 and 21.47, respectively. GMTs and NA seroprevalence for PV1, PV2 and PV3 in older people were lower than young people. There were significant differences in seroprevalences of PV1 and PV3 among geographic areas (P < .05) in Chongqing.High seroprevalence for PV1, PV2, and PV3 and qualified capability for monitoring AFP cases showed that the polio eradication program has made positive achievements in Chongqing and established a stable base for a polio vaccine immunization switch. Nevertheless, GMTs were negatively associated with age in the geographic districts with poor economical features, which will increase the risk of emergence of vaccine-derived PV after polio vaccine switch. More than 1 dose of inactivated polio vaccine should be introduced into the polio vaccine schedule, and the supplementary immunization of polio should still be annually carried out after polio vaccine switch, especially among elder children and the adults.
收集人群血清以评估重庆地区脊髓灰质炎免疫水平是否足够高，以满足脊髓灰质炎疫苗免疫策略转换的要求。2015年，按照不同地理特征在3个地区随机抽取了7个年龄组（<1岁、1 - 2岁、3 - 4岁、5 - 6岁、7 - 14岁、15 - 19岁、≥20岁）的人群。采集外周静脉血样本，并进行检测脊髓灰质炎病毒（PV）中和抗体的检测。收集2012年至2016年重庆地区急性弛缓性麻痹（AFP）数据，通过指标分析评估AFP监测系统的运行情况。共有636人接受了PV中和抗体（NA）检测。PV1、PV2和PV3的总体NA血清阳性率分别为93.40%、96.38%和91.82%，几何平均滴度（GMT）分别为61.14、66.78和21.47。老年人中PV1、PV2和PV3的GMT和NA血清阳性率低于年轻人。重庆地区不同地理区域之间PV1和PV3的血清阳性率存在显著差异（P<0.05）。PV1、PV2和PV3的高血清阳性率以及合格的AFP病例监测能力表明，重庆地区的脊髓灰质炎根除计划取得了积极成果，并为脊髓灰质炎疫苗免疫策略转换奠定了稳定基础。然而，在经济状况较差的地理区域，GMT与年龄呈负相关，这将增加脊髓灰质炎疫苗转换后疫苗衍生PV出现的风险。应在脊髓灰质炎疫苗接种程序中增加1剂以上的灭活脊髓灰质炎疫苗，并且在脊髓灰质炎疫苗转换后仍应每年开展脊髓灰质炎补充免疫，尤其是在大龄儿童和成人中。
