WEDNESDAY, April 8, 2026 (HealthDay News) -- In pediatric patients, influenza vaccine effectiveness (VE) varied across 2021 to 2024 seasons, but did help prevent influenza-associated hospitalizations and outpatient visits, according to a study published online April 6 in Pediatrics.
Samantha M. Olson, M.P.H., from the U.S. Centers for Disease Control and Prevention in Atlanta, and colleagues estimated VE against influenza-associated hospitalizations and outpatient visits during three influenza seasons (2021 to 2024) using data from seven U.S. pediatric medical centers. Children aged 6 months to 17 years who were hospitalized or received outpatient care for acute respiratory illness were included in the study.
Overall, 2,831 and 17,086 (14 and 86 percent) of the 19,917 children were positive and negative for influenza, respectively; 43 and 57 percent were vaccinated and unvaccinated, respectively. The researchers found that among children testing negative for influenza, vaccination uptake ranged from 44 to 51 percent by season. Across seasons, VE ranged from 34 to 60 percent, with the lowest estimates during 2021 to 2022. Effectiveness was 53, 43, and 69 percent against influenza A/H1N1, A/H3N2, and B, respectively, with additional variation by clade.
"Our study shows influenza VE ranged, but overall, was effective at preventing influenza-associated hospitalizations and outpatient visits in children aged 6 months to 17 years," the authors write. "Higher pediatric influenza vaccine coverage could amplify the benefits of vaccination among children."
Several authors disclosed ties to the biopharmaceutical industry.