实施水痘疫苗2剂次免疫程序对北京市西城区水痘发病的影响

Influence of two-dose immunization schedule of varicella vaccine on incidence in Xicheng District,Beijing

目的探讨北京市西城区实施水痘疫苗(varicella vaccine,VarV)1及2剂次免疫程序前后水痘的流行病学特征变化。方法采用描述流行病学方法对北京市西城区实施VarV 1剂次(2008~2012年,34 145人次)及2剂次(2013~2017年,77 213人次)免疫程序时期发病资料进行分析。结果 VarV 1剂次及2剂次免疫时期全区年均发病数分别为1 065和910例,年均发病率分别为86. 69/10万和64. 73/10万,高发季节均为每年12~1月冬季、4~6月春季,2剂次春季和冬季发病高峰略有下降。不同剂次免疫时期西城区15个街道发病率均下降,流动人口相对较多的广外和白纸坊街道发病率居前两位。随着疫苗接种量上升,除<1岁组和≥30岁组发病率呈现上升趋势(P <0. 05)外,其余年龄组发病率均下降,尤其是5~9岁组下降明显(P <0. 01)。1剂次及2剂次免疫程序期水痘暴发疫情年均分别为4. 2和4起,均发生在学校。结论 VarV 2剂次免疫程序有效降低了西城区水痘整体发病水平,但对降低局部暴发疫情不明显。建议加强成人VarV接种宣传,开展VarV免疫持久性研究。

Objective To analyze the changes in epidemiological characteristics of varicella before and after implementation of one-and two-dose immunizations schedule of varicella vaccine(VarV) in Xicheng District,Beijing City. Methods Descriptive epidemiological methods were used to analyze the data on incidence of varicella in Xicheng District during the implementation of one-dose(2008 ~ 2012,34 145 doses) and two-dose(2013 ~ 2017,77 213 doses) immunization schedules. Results The annual average case numbers of varicella during implementation of one-dose and two-dose immunization schedules were 1 065 and 910,while the annual average incidence rates were 86. 69 and 64. 73 per 100000 persons,respectively. Most of the cases appeared in the winter(December to January)and the spring(April to June).However,when the two-dose immunization schedule was implemented,both the peaks of incidence in winter and spring decreased slightly. The incidence rates in 15 communities in Xicheng District during implementation of one-and two-doseimmunization schedules decreased,of which the top two appeared in Guangwai and Baizhifang Communities with large floating populations. With the increasing quantity of vaccine inoculated,the incidences in the populations at ages of less than one and not less than 30 years showed increasing tendencies(P < 0. 05),while those in other age groups especially5 ~ 9 years decreased significantly(P < 0. 01). The average numbers of varicella outbreaks during implemen-tation of one-and two-dose immunization schedules were 4. 2 and 4. 0 per year respectively,both of which occurred in schools.Conclusion The two-dose immunization schedule of VarV significantly decreased the incidence of varicella in Xicheng District,while showed no influence on decreasing the local outbreak. It is suggested to strengthen the publicity of VarV vaccination for adults and study the persistence of VarV.