腮腺炎疫苗在学校暴发疫情中的保护效果调查

Effectiveness of Mumps Vaccine in Outbreaks in Schools

目的了解含腮腺炎成分疫苗(Mumps-containing Vaccine,Mu CV)在学校流行性腮腺炎暴发疫情中的保护效果,为完善Mu CV免疫策略提供依据。方法选取四川省某县区发生流行性腮腺炎暴发疫情的2所学校中病例数≥3例的班级内所有学生作为研究对象,采用回顾性调查和队列研究分析疫苗保护效果。结果共有723名学生被纳入研究对象,流腮总罹患率为15.4%(111/723),接种组罹患率为10.8%(60/557),未接种组罹患率为30.7%(51/166),接种过Mu CV的学生发生腮腺炎的风险是未接种者的35%(RR=0.35,95%CI:0.25~0.49),接种Mu CV是流腮发病的保护因素,疫苗保护效果(Vaccine Effectiveness,VE)为65%;接种2剂次Mu CV的VE为71%,高于接种1剂次Mu CV的62%;随着接种后时间的延长,罹患率呈逐年上升趋势,而VE呈下降趋势。结论接种Mu CV仍是预防和控制流腮最有效的措施,但免疫超过一定年限后疫苗保护效果有所下降。建议在广泛开展并保证1剂次Mu CV接种的基础上,在儿童入学前再加强1剂Mu CV,或者将接种程序由原来的1剂次增加到2剂次,从而提高疫苗的保护效率,降低儿童患流腮的风险。

Objective To investigate the effectiveness of Mumps-containing Vaccine（ Mu CV） in outbreaks in schools so as to provide a basis for improving the Mu CV immunization strategy. Methods All students in classes with ≥3 cases in two schools with outbreaks of mumps in a county in Sichuan Province were selected as the study subjects,and the effectiveness of the vaccine was evaluated by a retrospective investigation and a cohort study. Results A total of 723 students were included into the study. The total incidence of mumps was 15. 4%（ 111/723）. The incidence in the vaccinated group was 10. 8%（ 60/557）,and the incidence in the unvaccinated group was 30. 7%（ 51/166）. The risk of mumps in students having received Mu CV was 35% of that in students having not received Mu CV（ RR = 0. 35,95%CI： 0. 25-0. 49）. Immunization with Mu CV was a protective factor against mumps,and the vaccine effectiveness（ VE） rate was 65%. The VE rate following administration for 2 dose times was 71 %,higher than that following administration for 1 dose time（ 62 %）.With time going following immunization,the incidence increased yearly,while the VE showed a decreasing trend. Conclusion Mu CV administration is still the most effective measure to prevent and control mumps,but the vaccine effectiveness will decline after certain time following immunization. It is suggested that,on the basis of extensively carrying out and guaranteeing administration of Mu CV for 1 dose time,an additional dose of Mu CV be administered in children before they enter schools or the immunization schedule be adjusted from 1 dose time to 2 dose times so as to improve the vaccine effectiveness and reduce the risk of mumps in children.