Epidemiological evaluation for vaccine effectiveness of varicella attenuated live vaccine among students in collective institutions in Jing an District, Shanghai from 2017 to 2019
10.16835/j.cnki.1000-9817.2023.01.031
- VernacularTitle:上海市静安区2017—2019年集体机构学生水痘疫苗应急接种效果评估
- Author:
ZHANG Xiaojuan, AO Jianjun, YU Ping, QUAN Li, BEI Weihui, HUA Ruijue, HUANG Jin
1
Author Information
1. Immunization Planning Department， Center for Disease Control and Prevention, Jing an District, Shanghai (200072) , China
- Publication Type:Journal Article
- Keywords:
Chickenpox vaccine;
Vaccination;
Prevalence;
Students
- From:
Chinese Journal of School Health
2023;44(1):139-142
- CountryChina
- Language:Chinese
-
Abstract:
Objective:To understand the vaccination of varicella attenuated live vaccine (VarV) among students in collective institutions, to provide a basis for analying the protective effect of vaccination.
Methods:All collective institutions with chickenpox epidemic and post exposure vaccination in Jing an District from 2017 to 2019 were investigated. All students( n =6 473) in the affected class were included. Vaccination status and the incidence information of disease were collected to analyze vaccine effectiveness (VE).
Results:The proportion of study subjects without an immunization history decreased year by year, and 7.5% in 2017, 7.2 % in 2018, and 4.9% in 2019. The proportion with a history of one dose prior to exposure in cases was 90.0%, it was lower than 93.5% in the non cases ( χ 2=6.53, P <0.05). The proportion with one dose as post exposure prophylaxis in cases was 8.3%, it was much lower than 44.1% in the non cases ( χ 2=179.06, P <0.01). The proportion with one dose as post exposure prophylaxis in secondary cases was 28.6%, much lower than 44.1% in the non cases ( χ 2=9.44, P <0.01).Unvaccinated ones and the second dose as post exposure prophylaxis ones in cases had the highest rate of varicella development (11.0%), a history of one dose prior to exposure and one dose as post exposure prophylaxis in cases had the lowest varicella rate (1.0%).There was a clear protective effect within two years after one dose of VarV inoculation, VE was 63.1%(95% CI =11.0%-84.7%).
Conclusion:The vaccine effectiveness of one dose VarV was limited. Post exposure prophylaxis as early as possible was highly effective in decreasing secondary attack rate.
