Peer-reviewed article
Epidemiological characteristics of varicella and factors associated with breakthrough varicella among children aged 0-14 years in Jiangsu Province, China.
Mei Li, Yan Xu, Yurong Li, Qiang Chen, Chengmei Jia et al. ·
Summary
Written by AI, not yet AICS's view ·Key points
Limitations
Abstract
BACKGROUND: This study aimed to explore the epidemiological characteristics of varicella and breakthrough varicella (BV), as well as factors associated with the BV proportion during 2021-2024. RESEARCH DESIGN AND METHODS: Data on varicella cases aged 0-14 years were extracted from the national surveillance system and linked to individual immunization records. Logistic and linear regression were adopted. RESULTS: Among 162,844 cases, 34.3% were BV, and 10-14-year age group increased significantly from 24.7% in 2021 to 61.1% in 2024 (p < 0.001). During 2023-2024, older age groups showed lower BV proportion (5-9 years: OR = 0.49; 10-14 years: OR = 0.58; both p < 0.001), while the 10-14 years group showed higher BV proportion (OR = 1.08, p < 0.001) during 2021-2022. Autumn onset (OR = 1.14) and cases from central (OR = 1.39) and southern Jiangsu (OR = 2.31) were positively associated with BV proportion (all p < 0.001). The median breakthrough interval among one-dose recipients was 7.5 years, with 61.7% of cases occurring ≥6 years post-vaccination. CONCLUSION: Varicella burden in Jiangsu is shifting to older children. Strengthening two-dose varicella vaccination and maintaining routine vaccination coverage in young children are crucial for varicella control.