tetano
Editor, Senior Moderator
Vaccine
. 2026 Sep 6:92:129100.
doi: 10.1016/j.vaccine.2026.129100. Online ahead of print.
Jianhua Lu 1 , Zhiyao Ouyang 2 , Fang Huang 1 , Xu Xie 1 , Xin Wang 1 , Xiaoliang Wu 1 , Biyi Hu 2 , Jiatong Sun 3 , Min Jiang 1 , Ying Sun 1 , Hui Liu 1 , Yafang Zhong 2 , Quan Lu 4 , Guijian Dai 5 , Xiaozhen Chen 6 , Shisong Fang 7 , Yawen Jiang 8 , Yuelong Shu 9
Affiliations
Objective: To comprehensively evaluate the real-world effectiveness of the influenza vaccine among school-aged children across a dual-peak season, specifically examining subtype-specific protection, age variations, durability of protection over time, and the impact of repeated prior-season vaccination.
Methods: A test-negative design was used to assess vaccine effectiveness (VE) among school-aged children in Shenzhen. Based on questionnaire data and laboratory testing, patients with laboratory-confirmed influenza were classified as cases, while test-negative patients served as controls. Multivariable logistic regression was applied to compare the odds of vaccination between cases and controls.
Results: Among 1669 eligible participants (463 cases and 1206 test-negative controls), the overall adjusted VE against medically attended influenza was 46.36% (95% CI: 29.23-59.34%). VE differed across age groups and was mainly observed in younger children. Significant protection was observed within 14-119 days post-vaccination, became non-significant during 120-239 days, and re-emerged during the summer peak at 240-299 days. Prior-season vaccination alone provided no significant residual protection, while repeated vaccination across two consecutive seasons was associated with reduced effectiveness in the current season. Subtype-specific VE was 43.48% (95% CI: 18.00-61.04%) against influenza A(H1N1), 34.42% (95% CI: 0.55-56.76%) against influenza A(H3N2), and 56.95% (95% CI: 7.68-79.93%) against the B/Victoria lineage. During the winter-spring peak, VE was 49.84% (95% CI: 26.90-65.59%).
Conclusions: Influenza vaccine provided moderate effectiveness against influenza-associated outpatient visits among school-aged children in Shenzhen during the 2024-2025 season.
Keywords: Influenza; Student; Surveillance; Test-negative design; Vaccine effectiveness.
. 2026 Sep 6:92:129100.
doi: 10.1016/j.vaccine.2026.129100. Online ahead of print.
Real-world effectiveness of the influenza vaccine among school-aged children in Shenzhen, China, 2024-2025 season: A test-negative design study
Jianhua Lu 1 , Zhiyao Ouyang 2 , Fang Huang 1 , Xu Xie 1 , Xin Wang 1 , Xiaoliang Wu 1 , Biyi Hu 2 , Jiatong Sun 3 , Min Jiang 1 , Ying Sun 1 , Hui Liu 1 , Yafang Zhong 2 , Quan Lu 4 , Guijian Dai 5 , Xiaozhen Chen 6 , Shisong Fang 7 , Yawen Jiang 8 , Yuelong Shu 9
Affiliations
- PMID: 42702143
- DOI: 10.1016/j.vaccine.2026.129100
Abstract
Objective: To comprehensively evaluate the real-world effectiveness of the influenza vaccine among school-aged children across a dual-peak season, specifically examining subtype-specific protection, age variations, durability of protection over time, and the impact of repeated prior-season vaccination.
Methods: A test-negative design was used to assess vaccine effectiveness (VE) among school-aged children in Shenzhen. Based on questionnaire data and laboratory testing, patients with laboratory-confirmed influenza were classified as cases, while test-negative patients served as controls. Multivariable logistic regression was applied to compare the odds of vaccination between cases and controls.
Results: Among 1669 eligible participants (463 cases and 1206 test-negative controls), the overall adjusted VE against medically attended influenza was 46.36% (95% CI: 29.23-59.34%). VE differed across age groups and was mainly observed in younger children. Significant protection was observed within 14-119 days post-vaccination, became non-significant during 120-239 days, and re-emerged during the summer peak at 240-299 days. Prior-season vaccination alone provided no significant residual protection, while repeated vaccination across two consecutive seasons was associated with reduced effectiveness in the current season. Subtype-specific VE was 43.48% (95% CI: 18.00-61.04%) against influenza A(H1N1), 34.42% (95% CI: 0.55-56.76%) against influenza A(H3N2), and 56.95% (95% CI: 7.68-79.93%) against the B/Victoria lineage. During the winter-spring peak, VE was 49.84% (95% CI: 26.90-65.59%).
Conclusions: Influenza vaccine provided moderate effectiveness against influenza-associated outpatient visits among school-aged children in Shenzhen during the 2024-2025 season.
Keywords: Influenza; Student; Surveillance; Test-negative design; Vaccine effectiveness.