tetano
Editor, Senior Moderator
Open Forum Infect Dis
. 2026 Aug 4;13(8)
fag473.
doi: 10.1093/ofid/ofag473. eCollection 2026 Aug.
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[SUP] 1 [/SUP], Emily L Reeves[SUP] 1 [/SUP], Zachary A Weber[SUP] 2 [/SUP], Duck-Hye Yang[SUP] 2 [/SUP], Stephanie A Irving[SUP] 3 [/SUP], Sara Y Tartof[SUP] 4 5 [/SUP], Nicola P Klein[SUP] 6 [/SUP], Shaun J Grannis[SUP] 7 8 [/SUP], Toan C Ong[SUP] 9 [/SUP], Sarah W Ball[SUP] 2 [/SUP], Malini B DeSilva[SUP] 10 [/SUP], Kristin Dascomb[SUP] 11 [/SUP], Allison L Naleway[SUP] 3 [/SUP], Padma Koppolu[SUP] 3 [/SUP], S Bianca Salas[SUP] 4 [/SUP], Lina S Sy[SUP] 4 [/SUP], Bruno Lewin[SUP] 4 5 [/SUP], Richard Contreras[SUP] 4 [/SUP], Ousseny Zerbo[SUP] 6 [/SUP], John R Hansen[SUP] 6 [/SUP], Lawrence Block[SUP] 6 [/SUP], Karen B Jacobson[SUP] 6 [/SUP], Brian E Dixon[SUP] 7 12 [/SUP], Colin Rogerson[SUP] 7 8 [/SUP], Thomas Duszynski[SUP] 7 12 [/SUP], William F Fadel[SUP] 7 12 [/SUP], Michelle A Barron[SUP] 9 [/SUP], David Mayer[SUP] 9 [/SUP], Catia Chavez[SUP] 9 [/SUP], Adam Yates[SUP] 2 [/SUP], Lindsey Kirshner[SUP] 2 [/SUP], Charlene E McEvoy[SUP] 10 13 [/SUP], Omobosola O Akinsete[SUP] 10 14 [/SUP], Inih J Essien[SUP] 10 [/SUP], Tamara Sheffield[SUP] 11 15 [/SUP], Daniel Bride[SUP] 11 16 [/SUP], Julie Arndorfer[SUP] 11 [/SUP], Josh Van Otterloo[SUP] 11 [/SUP], Karthik Natarajan[SUP] 17 18 [/SUP], Caitlin S Ray[SUP] 1 [/SUP], Amanda B Payne[SUP] 1 [/SUP], Katherine Adams[SUP] 1 [/SUP], Brendan Flannery[SUP] 1 [/SUP], Shikha Garg[SUP] 1 [/SUP]
Affiliations
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.
Keywords: case-control studies; influenza; test-negative design; vaccination; vaccine effectiveness.
. 2026 Aug 4;13(8)
fag473.doi: 10.1093/ofid/ofag473. eCollection 2026 Aug.
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[SUP] 1 [/SUP], Emily L Reeves[SUP] 1 [/SUP], Zachary A Weber[SUP] 2 [/SUP], Duck-Hye Yang[SUP] 2 [/SUP], Stephanie A Irving[SUP] 3 [/SUP], Sara Y Tartof[SUP] 4 5 [/SUP], Nicola P Klein[SUP] 6 [/SUP], Shaun J Grannis[SUP] 7 8 [/SUP], Toan C Ong[SUP] 9 [/SUP], Sarah W Ball[SUP] 2 [/SUP], Malini B DeSilva[SUP] 10 [/SUP], Kristin Dascomb[SUP] 11 [/SUP], Allison L Naleway[SUP] 3 [/SUP], Padma Koppolu[SUP] 3 [/SUP], S Bianca Salas[SUP] 4 [/SUP], Lina S Sy[SUP] 4 [/SUP], Bruno Lewin[SUP] 4 5 [/SUP], Richard Contreras[SUP] 4 [/SUP], Ousseny Zerbo[SUP] 6 [/SUP], John R Hansen[SUP] 6 [/SUP], Lawrence Block[SUP] 6 [/SUP], Karen B Jacobson[SUP] 6 [/SUP], Brian E Dixon[SUP] 7 12 [/SUP], Colin Rogerson[SUP] 7 8 [/SUP], Thomas Duszynski[SUP] 7 12 [/SUP], William F Fadel[SUP] 7 12 [/SUP], Michelle A Barron[SUP] 9 [/SUP], David Mayer[SUP] 9 [/SUP], Catia Chavez[SUP] 9 [/SUP], Adam Yates[SUP] 2 [/SUP], Lindsey Kirshner[SUP] 2 [/SUP], Charlene E McEvoy[SUP] 10 13 [/SUP], Omobosola O Akinsete[SUP] 10 14 [/SUP], Inih J Essien[SUP] 10 [/SUP], Tamara Sheffield[SUP] 11 15 [/SUP], Daniel Bride[SUP] 11 16 [/SUP], Julie Arndorfer[SUP] 11 [/SUP], Josh Van Otterloo[SUP] 11 [/SUP], Karthik Natarajan[SUP] 17 18 [/SUP], Caitlin S Ray[SUP] 1 [/SUP], Amanda B Payne[SUP] 1 [/SUP], Katherine Adams[SUP] 1 [/SUP], Brendan Flannery[SUP] 1 [/SUP], Shikha Garg[SUP] 1 [/SUP]
Affiliations
- PMID: 42614619
- PMCID: PMC13481979
- DOI: 10.1093/ofid/ofag473
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.
Keywords: case-control studies; influenza; test-negative design; vaccination; vaccine effectiveness.