Impact of optimized varicella vaccination strategy on varicella incidence among nursery children in Shenzhen
10.16835/j.cnki.1000-9817.2026142
- VernacularTitle:水痘疫苗接种策略优化对深圳市托幼机构儿童水痘发病率影响
- Author:
WEN Ying, CHEN Nixuan, LI Yingying, LIU Tingting, CHENG Yanpeng, ZHANG Yingluan, L Qiuying, KONG Dongfeng, CHEN Zhigao, ZHANG Zhen, LU Jianhua
1
Author Information
1. Department of Infectious Disease Control and Prevention, Shenzhen Center for Disease Control and Prevention, Shenzhen 518055, Guangdong Province, China
- Publication Type:Journal Article
- Keywords:
Chickenpox；Chickenpox vaccine；Vaccination；Incidence；Child
- From:
Chinese Journal of School Health
2026;47(5):728-731
- CountryChina
- Language:Chinese
-
Abstract:
Objective:To analyze the epidemiological characteristics of varicella among nursery children in Shenzhen from 2015 to 2024, and to evaluate the impact of optimizing varicella vaccine (VarV) immunization strategies on varicella incidence.
Methods:Varicella incidence data for nursery children in Shenzhen from 2015 to 2024 were obtained from the China Disease Prevention and Control Information System. The study period was divided into three phases:one dose self pay VarV (January 2015 to October 2017), two dose self pay VarV (November 2017 to October 2019), and two dose free VarV (November 2019 to December 2024). Interrupted time series (ITS) analysis was conducted to assess changes in the level and trend of varicella incidence associated with each phase of policy implementation.
Results:A total of 27 517 varicella cases was reported among nursery children from 2015 to 2024, with an average annual incidence of 514.01/100 000. During the same period, 136 clustered outbreaks were reported in nursery institutions, involving a cumulative total of 1 091 cases. ITS analysis showed that during the self pay 1 dose stage, the varicella incidence among nursery children showed an upward trend, with an average monthly increase of 2.58/100 000 (95% CI =2.21/ 100 000 -2.95/100 000, P <0.01). After the implementation of the self pay 2 dose strategy, the incidence decreased, with a change in incidence of -26.12/100 000 (95% CI =-37.30/100 000 to -14.94/100 000) and a change in slope of -2.65/100 000 (95% CI = -3.38/100 000 to -1.93/100 000)(all P <0.01). After the implementation of the free 2 dose strategy, the incidence decreased further, with a change in incidence of -40.03/100 000 (95% CI =-50.39/100 000 to -29.66/100 000, P <0.01) and a change in slope of -0.56/100 000 (95% CI =-1.20/100 000-0.08/100 000, P =0.09).
Conclusion:The gradual optimization of the VarV vaccination strategy in Shenzhen from self pay 1 dose to free 2 dose has significantly reduced the varicella incidence among nursery children, demonstrating good short term control and long term intervention effectiveness.
