ArticleClinical infectious diseases : an official publication of the Infectious Diseases Society of America2025
Influenza Vaccine Effectiveness Against Medically Attended Outpatients Illness, United States, 2023-2024 Season.
Article in Clinical infectious diseases : an official publication of the Infectious Diseases Society of America, 2025. The graph could read no effect estimate from its abstract, so it casts no vote on the map. Cited by 24 papers.
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The abstract states no effect estimate the extractor could read, or names no intervention and outcome on the map, so this paper lights no cell and moves no belief. It is still indexed, cited and linked below.
The trial behind it
Trials whose registry record cites this paper, or whose number appears in the abstract. A trial that started after this paper was published is citing it as background, not reporting it.
Neither the registry nor the abstract names a trial number. If this is a trial report, that itself is worth knowing.
Who cites it
24 citing papers in PubMed.
- Influenza Vaccine Effectiveness Against Influenza-Associated Hospitalizations and Emergency Department or Urgent Care Encounters Among Children and Adults-VISION, United States, 2024-2025 Season.Open forum infectious diseases · 2026Article
- Effectiveness of seasonal influenza vaccine against dominant A(H1N1)pdm09 in adults ≥ 60 years: a multicenter test-negative design in Zhejiang, China, 2024-2025.BMC geriatrics · 2026Observational
- Influenza vaccine effectiveness against outpatient acute respiratory illness with laboratory-confirmed influenza, United States, 2024-25 season.Clinical infectious diseases : an official publication of the Infectious Diseases Society of America · 2026Article
- Strain-specific differences in the response to egg-derived versus recombinant protein influenza vaccines.Journal of virology · 2026Article
- Influenza Vaccine and Associated Infection and Death in California, 2024 to 2025.JAMA network open · 2026Article
- Influenza vaccine effectiveness against influenza-associated hospitalizations and emergency department or urgent care encounters among children and adults - United States, 2024-25 season.medRxiv : the preprint server for health sciences · 2026Article
- Strain-specific differences in the response to egg-derived versus recombinant protein influenza vaccines.bioRxiv : the preprint server for biology · 2026Article
- Article
- Effectiveness of 2024/25 KP.2 Vaccine Against Outpatient COVID-19 in Canada.Influenza and other respiratory viruses · 2026Article
- Influenza vaccine effectiveness from nine studies during drifted A(H3N2) subclade K predominance, Europe, September 2025 to January 2026.Euro surveillance : bulletin Europeen sur les maladies transmissibles = European communicable disease bulletin · 2026Article
- Influenza Vaccine Effectiveness Among Children With and Without Underlying Conditions.Pediatrics · 2026Article
- Next-generation intranasal influenza vaccines: mechanisms, platforms, and translational progress.Frontiers in immunology · 2026Review
- Superior Effectiveness and Estimated Public Health Impact of Cell- Versus Egg-Based Influenza Vaccines in Children and Adults During the US 2023-2024 Season.Infectious diseases and therapy · 2025Article
- Estimating Influenza Vaccine Effectiveness Against Laboratory-Confirmed Influenza Using Linked Public Health Information Systems, California, 2023-2024 Season.The Journal of infectious diseases · 2025Article
- Vaccine Effectiveness Against Influenza A(H1N1), A(H3N2), and B-Associated Hospitalizations, United States, 1 September 2023 to 31 May 2024.The Journal of infectious diseases · 2025Article
- Seasonal Influenza: A Narrative Review of Epidemiology, Clinical Features, and Preventive Strategies.Cureus · 2025Review
- Influenza Vaccine Effectiveness During the 2023/2024 Season: A Test-Negative Case-Control Study Among Emergency Hospital Admissions With Respiratory Conditions in Northern Ireland.Influenza and other respiratory viruses · 2025Article
- Effectiveness of Cell Culture-Based Influenza Vaccine, 2023-2024.Journal of the Pediatric Infectious Diseases Society · 2025Article
- Incidence of Circulating Antibodies Against Hemagglutinin of Influenza Viruses in Epidemic Season 2023/2024 in Poland.Biomolecules · 2025Article
- Influenza vaccine effectiveness in Europe and the birth cohort effect against influenza A(H1N1)pdm09: VEBIS primary care multicentre study, 2023/24.Euro surveillance : bulletin Europeen sur les maladies transmissibles = European communicable disease bulletin · 2025Article
Corrections and comments
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Authors and funding
23 authors.
Funding
Abstract
backgroundThe 2023-2024 US influenza season was characterized by a predominance of A(H1N1)pdm09 virus circulation with cocirculation of A(H3N2) and B/Victoria viruses. We estimated vaccine effectiveness (VE) in the United States against mild-to-moderate medically attended influenza illness in the 2023-2024 season.
methodsWe enrolled outpatients aged ≥8 months with acute respiratory illness in 7 states. Respiratory specimens were tested for influenza type/subtype by reverse-transcriptase polymerase chain reaction. Influenza VE was estimated with a test-negative design comparing odds of testing positive for influenza among vaccinated versus unvaccinated participants. We estimated VE by virus subtype/lineage and A(H1N1)pdm09 genetic subclades.
resultsAmong 6629 enrolled patients, 1780 (27%) tested positive for influenza, including 806 with A(H1N1)pdm09, 567 with B/Victoria, and 328 with A(H3N2). VE against any influenza illness was 44% (95% confidence interval, 36%-51%): 29% (15%-41%) against influenza A(H1N1)pdm09, 74% (65%-81%) against B/Victoria, and 30% (8%-47%) against A(H3N2). Statistically significant protection against any influenza was found for all age groups except adults aged 50-64 years. Lack of protection in this age group was specific to influenza A-associated illness. We observed differences in VE by birth cohort and A(H1N1)pdm09 virus genetic subclade.
conclusionsVaccination reduced outpatient medically attended influenza overall by 44% and provided protection overall against circulating influenza A and B viruses. Serologic studies would help inform differences observed by age groups.
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Read under generation 80e0d062 · epoch 390. Bibliography from PubMed, PubMed Central and OpenAlex; grants from NIH RePORTER; trial links from ClinicalTrials.gov; estimates, votes and beliefs from the OpenQuestion graph.