A comprehensive review published in JAMA confirms ongoing strong protection from flu vaccines, especially in high-risk populations, amid changing policies and updated vaccine formulations for the 2026-27 season.
A fresh evidence review has bolstered the case for annual influenza vaccination, finding that the shots continued to lower the risk of severe illness, hospital admission and death across multiple seasons, with the strongest benefits seen in older adults, infants, children and young adults. The review, published in JAMA and led through the Vaccine Integrity Project at the University of Minnesota in partnership with the American Medical Association, found no new safety concerns, adding to a body of evidence that public-health experts say remains especially important as flu continues to drive substantial winter illness. According to the project, influenza vaccination remains “one of our best tools for preventing severe illness from respiratory viruses,” as Michael T. Osterholm said in a news release.
The review updated an earlier evidence search and examined English-language studies published between August 1, 2025, and June 30, 2026. Investigators screened 5,826 records and included 69 studies in total, ranging from randomised clinical trials to observational research and descriptive studies of disease burden. The findings come after a heavy 2025-26 flu season that the Centres for Disease Control and Prevention estimated caused between 15 million and 25 million medical visits, 390,000 and 800,000 hospitalisations and at least 24,000 deaths, even though fewer than half of eligible adults and children received a flu vaccine.
Among older adults, the evidence continued to show meaningful protection against severe outcomes. Data from the VISION Network found vaccination reduced the risk of influenza-related hospitalisation by 31% in adults aged 65 and older during the 2025-26 season, and by 29% in adults aged 18 to 64. In the prior season, vaccine effectiveness against influenza-related death in older adults ranged from 29% to 65.8%. The review also found that formulation mattered: in Denmark, the DANFLU-2 trial involving more than 332,000 older adults found high-dose quadrivalent inactivated vaccine was more protective against influenza-related hospitalisation than standard-dose vaccine over three seasons.
The benefits were also substantial in children and pregnant people. In children and adolescents aged 6 months to 17 years, vaccine effectiveness against influenza-related hospitalisation ranged from 28% to 67% across seasons. National surveillance data over eight seasons showed vaccination was associated with an 80% reduction in influenza-related deaths among children, including a 77% reduction among those with high-risk medical conditions, with most paediatric deaths occurring in unvaccinated children. Vaccination during any trimester of pregnancy was linked to a 44.4% reduction in laboratory-confirmed influenza among infants during their first six months of life.
Safety findings were similarly reassuring. The review drew on a self-controlled case series involving nearly 10 million commercially insured people and found no significant increase in Guillain-Barré syndrome, anaphylaxis or stroke after standard-dose vaccination. Among young children, flu shots were not associated with a higher risk of febrile seizure, and vaccination during pregnancy was not linked to preterm birth. The review also found no safety concerns when flu vaccines were given alongside COVID-19 or respiratory syncytial virus vaccines.
The evidence review arrives as the US flu programme enters a more unsettled policy period. Before 2025, the Advisory Committee on Immunization Practices regularly reviewed vaccine data to guide national recommendations, but that process was disrupted when the Department of Health and Human Services dismissed the panel’s members. In the absence of a restored expert committee, four medical societies used the review to shape their 2026-27 guidance. The American Academy of Family Physicians recommends an updated flu vaccine for everyone aged 6 months to 64 years and suggests mRNA, adjuvanted, high-dose or recombinant options for adults 65 and older. The American Academy of Pediatrics recommends annual vaccination for everyone older than 6 months. The Infectious Diseases Society of America advises high-dose, adjuvanted, inactivated or recombinant vaccines for immunocompromised patients and says live attenuated vaccines should not be used in that group. The American College of Obstetricians and Gynecologists recommends inactivated or recombinant vaccines during pregnancy and after birth.
That guidance is being set against a backdrop of updated vaccine composition for the 2026-27 season. The CDC says vaccines for the coming flu season are designed to target the influenza A(H3N2) subclade K virus that circulated widely last season, while the FDA has detailed strain selections for egg-based, cell-based and recombinant products. The agencies say an adequate and diverse supply is expected, and the CDC continues to recommend annual flu vaccination for everyone aged 6 months and older.
Disclaimer: This content is for informational purposes only and is not intended to be a substitute for professional medical judgment, advice, diagnosis, or treatment.
