International journal of infectious diseases : IJID : official publication of the International Society for Infectious Diseases · 2026
Influenza vaccine effectiveness in school outbreaks during a A(H3N2) subclade K (J.2.4.1)-dominated season in Beijing, China, 2025-26.
СтатьяНазвание и аннотация: Перевод пока не подготовлен
Обработка статьи · этапы, ошибки и управление
Загрузка состояния…
Ошибки и ограничения
История · было → стало
Состояние обновляется каждые 5 секунд, пока блок открыт. Процент показывается только там, где известен объём работы. Пауза останавливает продолжение этапа; текущий запрос к источнику может завершиться.
Shen Ying, Ma Chunna, Zhang Daitao, Shi Weixian, Duan Wei, Li Jia, Zhang Lu, Wu Dan, Zhang Jiaojiao, Ma Jiaxin, Wang Yingying, Hu Xiaodi, Yan Shuning, Di Yuanzhi, Zhao Jiachen, Xu Hui, Lu Guilan, Liu Yimeng, Wang Quanyi, Yang Peng, Feng Zhaomin
Аннотация
OBJECTIVES: Schools are high-risk settings for influenza transmission. During the 2025-26 Northern Hemisphere season, influenza A(H3N2) subclade K (J.2.4.1) rapidly emerged and became predominant, but vaccine effectiveness (VE) in school-associated outbreaks remains unclear.
METHODS: We conducted a field investigation of 93 school-associated febrile outbreaks in Beijing, China, from September to December 2025. Cases were febrile students with laboratory-confirmed influenza, and afebrile classmates served as controls. VE against laboratory-confirmed symptomatic infection was estimated using mixed-effects logistic regression, adjusting for age, sex, school type, and outbreak-level clustering.
RESULTS: A total of 3797 students were included, of whom 788 were laboratory-confirmed febrile cases and 3009 were afebrile classmates. Primary schools accounted for 74.2% of outbreaks. Overall vaccination rate was 54.6%, with 50.6% among cases and 56.1% among controls. Unadjusted VE was 19.6% (95% CI: 5.9-31.3). After adjustment, VE against laboratory-confirmed influenza was 30.0% (95% CI: 17.3-40.7). Sensitivity analyses yielded consistent results.
CONCLUSION: Influenza vaccination provided modest protection against symptomatic A(H3N2) infection in school-aged children, even under conditions of high-intensity exposure and antigenic drift. These findings underscore the value of vaccination in outbreak-prone school settings and highlight the importance of ongoing vaccine strain optimization and outbreak-based VE surveillance.
METHODS: We conducted a field investigation of 93 school-associated febrile outbreaks in Beijing, China, from September to December 2025. Cases were febrile students with laboratory-confirmed influenza, and afebrile classmates served as controls. VE against laboratory-confirmed symptomatic infection was estimated using mixed-effects logistic regression, adjusting for age, sex, school type, and outbreak-level clustering.
RESULTS: A total of 3797 students were included, of whom 788 were laboratory-confirmed febrile cases and 3009 were afebrile classmates. Primary schools accounted for 74.2% of outbreaks. Overall vaccination rate was 54.6%, with 50.6% among cases and 56.1% among controls. Unadjusted VE was 19.6% (95% CI: 5.9-31.3). After adjustment, VE against laboratory-confirmed influenza was 30.0% (95% CI: 17.3-40.7). Sensitivity analyses yielded consistent results.
CONCLUSION: Influenza vaccination provided modest protection against symptomatic A(H3N2) infection in school-aged children, even under conditions of high-intensity exposure and antigenic drift. These findings underscore the value of vaccination in outbreak-prone school settings and highlight the importance of ongoing vaccine strain optimization and outbreak-based VE surveillance.