Retracted article: Moderate protection from vaccination against influenza A(H3N2) subclade K in Beijing, China, September to December 2025

作者：Ying Shen, Daitao Zhang, Zhaomin Feng, Chunna Ma, Weixian Shi, Wei Duan, Jie Li, Lu Zhang, Dan Wu, J J Zhang, Jiaxin Ma, Yingying Wang, Xiaodi Hu, Shuning Yan, Yuanzhi Di, Jiachen Zhao, Hui Xu, Quanyi Wang, Peng Yang · 发表于：Eurosurveillance · 年份：2026 · DOI：10.2807/1560-7917.es.2026.31.2.2500993 · 被引用次数：5 · 研究领域：Influenza Virus Research Studies、Respiratory viral infections research、SARS-CoV-2 and COVID-19 Research

During the early 2025/26 influenza season, influenza A(H3N2) subclade K rapidly predominated in Beijing, China. Using a test-negative design, we estimated influenza vaccine effectiveness (VE) among influenza-like illness outpatients tested between September and December 2025. Among 9,579 participants, sequencing of 316 randomly selected A(H3N2)-positive samples showed 84.8% were subclade K, and antigenic analysis of 65 viruses indicated antigenic divergence. Despite this, adjusted VE against laboratory-confirmed influenza was 41.3% (95% CI: 29.2 to 51.3), indicating moderate protection during this subclade K-dominated season.