北京市昌平区6岁儿童加强接种前后麻疹、流行性腮腺炎和风疹抗体水平监测分析

Surveillance for measles, mumps and rubella antibody levels before and after booster immunization in children aged 6 years in Changping, Beijing

目的分析北京市昌平区6岁儿童加强接种疫苗前后麻疹、流行性腮腺炎和风疹抗体水平变化,为控制相应传染病,完善相关免疫策略提供依据。方法采用分层随机抽样法,将昌平区20个镇街分成3个等级镇街,每级镇街随机抽取2个镇街,共6个镇街作为监测现场。每个镇街随机选取6岁儿童作为免疫水平监测对象,依据知情同意的原则,共入组308名儿童,各采集静脉血3 ml,用ELISA试剂盒定量检测麻疹、腮腺炎和风疹IgG抗体水平,在接种麻疹、腮腺炎、风疹疫苗(麻腮风疫苗,MMR)后35~42 d,共采集274名儿童静脉血各3 ml,分析接种MMR前后麻疹、腮腺炎和风疹IgG抗体阳性率及抗体水平变化。结果加强MMR接种前,麻疹、腮腺炎和风疹抗体阳性率分别为94.16%、87.99%和72.40%,加强接种后三者抗体阳性率均为100.00%。麻疹、腮腺炎和风疹抗体几何平均浓度(GMC)加强接种前分别为999 mIU/ml、469 U/ml和44 IU/ml,接种后分别为1 700 mIU/ml、2 293 U/ml和107 IU/ml。加强接种前后三者抗体阳性率和GMC均升高,差异均有统计学意义(阳性率比较χ2=16.524、35.150和88.549,P=0.001;GMC比较t=-7.425、-10.001和-16.913,P=0.001)。结论 MMR加强接种前抗体阳性率下降,风疹和腮腺炎抗体阳性率较低,接种后风疹和腮腺炎抗体阳性率上升明显,昌平区6岁儿童麻腮风疫苗加强免疫效果良好,应继续保持较高的疫苗接种率。

Objective To monitor the antibody levels against measles, mumps and rubella before and after the booster immunization of measles- mumps- rubella （MMR） vaccine in children aged 6 years in Changping district of Beijing, and provide evidence for the control of related diseases and the improvement of immunization strategy. Methods Healthy children aged 6 years were selected in a multistage stratified sampling in 6 townships in Changping. A total of 308 children were selected for pre-vaccination antibody level detection by using venous blood samples （3 ml for each） collected from them based on the principal of informed consent, and the IgG levels against measles, mumps and rubella were detected by using ELISA kit. After booster immunization, 274 venous blood samples （3 ml for each） were collected from them at 35~h - 42na day to detect the IgG levels. Results Before the booster immunization, the positive rates of measles, mumps and rubella antibodies were 94.16%, 87.99% and 72.40%, while the geometric mean concentrations（GMCs）were 999 mIU/ml, 469 U/ml and 44 IU/ml, respectively. After the booster immunization, the positive rates of measles, mumps and rubella antibodies were all 100%, and the GMCs were 1 700 mIU/ml, 2 293 U/ml and 107 IU/ml, respectively. Both the antibody positive rates and GMCs increased after the booster immunization and the differences were significant. Conclusion Before the booster immunization, the positive rates of the IgG declined, especially the positive rates of mumps and rubella antibodies. But the IgG level of mumps and rubella increased significantly after the booster immunization. Current booster immunization program of MMR vaccine in Changping is effective, which can facilitate not only the elimination of measles but also the control of mumps and rubella. It is necessary to maintain the high coverage of MMR vaccine booster immunization.