Flu Vaccine

CDC interim analysis from September 2025 to February 2026 shows this season's flu vaccine effectiveness at 22-34% against outpatient visits for adults and 30-41% for those 65+, with hospitalization protection at 30-31%, due to H3N2 strain mismatch. The season saw 27 million illnesses, 350,000 hospitalizations, and 22,000 deaths, lower than last year's peaks but with 101 child deaths, 85% unvaccinated. Despite flaws, experts like Dr. William Schaffner stress shots prevent severe outcomes, with adult rates at 46.5%. Vaccination campaigns will target improved strains for next season.

CDC studies from September 2025 to February 2026 estimate flu vaccine effectiveness (VE) at 22-34% against influenza A/B outpatient visits for adults and 30-41% for those 65+, with 30-31% against hospitalizations. Patrick Maloney, PhD, from CDC's National Center for Immunization and Respiratory Diseases, led the analysis. Low VE underscores need for improved formulations amid slumping protection. Findings inform next season's vaccine development.

An FDA advisory committee has recommended the development of next year's flu vaccine, as new data from the CDC indicates the current 2025-2026 flu vaccine provides moderate protection against hospitalization for vaccinated individuals despite concerns about late-emerging H3N2 strains. The committee reviewed winter flu shot effectiveness reports published in the CDC's online MMWR journal, which showed moderate protective efficacy against severe outcomes requiring hospitalization. The timing of vaccine selection remains critical as late-emerging H3N2 variants can significantly undermine vaccine effectiveness, a concern flagged by the committee during this year's review. Current guidance continues to emphasize vaccination for those at high risk of severe illness, particularly elderly and immunocompromised populations.