Open access

Influenza Vaccine Effectiveness Against Influenza-Associated Hospitalizations and Emergency Department or Urgent Care Encounters Among Children and Adults-VISION, United States, 2024-2025 Season.

Jennifer DeCuir Emily L. Reeves Zachary A. Weber Duck-Hye Yang Stephanie A. Irving S. Tartof Nicola P. Klein S. Grannis Toan C. Ong Sarah W. Ball M. DeSilva Kristin Dascomb A. Naleway Padma Koppolu S. B. Salas L. S. Sy B.J. Lewin Richard Contreras O. Zerbo John R. Hansen Lawrence Block Karen B. Jacobson Brian E. Dixon Colin M. Rogerson Thomas J Duszynski William F. Fadel M. Barron D. Mayer Catia Chavez Adam M. Yates Lindsey Kirshner C. Mcevoy Omobosola O. Akinsete Inih J. Essien Tamara Sheffield Daniel Bride Julie Arndorfer J. Van Otterloo Karthik Natarajan Caitlin Ray A. Payne Katherine Adams Brendan Flannery S. Garg

Aug 2026 · Open Forum Infectious Diseases · Vol 13 8, pp. ofag473 · 0 citations

Medicine

Abstract

Background The 2024-2025 influenza season was the most severe in the United States (US) since 2017-2018, with co-circulation of both influenza A virus subtypes (H1N1 and H3N2). Influenza vaccine effectiveness (VE) has varied by season, setting, and patient characteristics. Methods Using electronic healthcare encounter data from 7 VISION sites in 8 US states, we evaluated influenza VE against influenza-associated hospitalizations and emergency department or urgent care (ED/UC) encounters from October 2024 to April 2025 among children aged 6 months-17 years and adults aged ≥18 years. Using a test-negative, case-control design, we compared the odds of influenza vaccination between acute respiratory illness encounters with a positive (cases) versus negative (controls) test for influenza by molecular assay, adjusting for confounders. Results Analyses included 108 618 encounters (5764 hospitalizations and 102 854 ED/UC encounters) among children and 309 483 encounters (76 072 hospitalizations and 233 411 ED/UC encounters) among adults. Among children across care settings, 17.0% (6097/35 765) of cases versus 29.4% (21 449/72 853) of controls were vaccinated. Among adults, 28.2% (21 832/77 477) of cases versus 44.2% (102 560/232 006) of controls were vaccinated. VE was 51% (95% confidence interval [95% CI]: 41%-60%) against influenza-associated hospitalizations and 54% (95% CI: 52%-55%) against influenza-associated ED/UC encounters among children. VE was 43% (95% CI: 41%-46%) against influenza-associated hospitalizations and 49% (95% CI: 47%-50%) against influenza-associated ED/UC encounters among adults. Conclusions Influenza vaccination provided protection against influenza-associated hospitalizations and ED/UC encounters among children and adults in the US during the severe 2024-2025 influenza season. These findings support influenza vaccination as an important tool to reduce influenza.

DOI PubMed Semantic Scholar

Read PDF