Influenza Vaccine Effectiveness Among Children With and Without Underlying Conditions.
Document Type
Article
Publication Date
2-1-2026
Identifier
DOI: 10.1542/peds.2025-072184
Abstract
OBJECTIVE: Children with certain underlying conditions are at higher risk for severe influenza-related complications. In the United States, annual influenza vaccination is recommended for all children aged 6 months and older, yet vaccine effectiveness (VE) in children with underlying conditions remains less understood. We assessed VE against laboratory-confirmed influenza in children with and without underlying conditions presenting to emergency departments or admitted to hospitals.
METHODS: We enrolled US children aged 6 months to 17 years at 7 pediatric medical centers within the New Vaccine Surveillance Network during 5 influenza seasons (2015-2020). Influenza status was confirmed by molecular testing and vaccination status was verified using state immunization registries or from health care clinicians. Underlying conditions were abstracted from medical records or self-reported by parents/guardians. VE was estimated by comparing the odds of vaccination among influenza-positive cases vs controls, adjusting for age, site, and calendar time.
RESULTS: Of the 15 875 children included, 2821 (18%) tested positive for influenza. Overall, VE against influenza-associated emergency department visits or hospitalizations was 43% (95% CI: 35%-50%) for children with underlying conditions and 53% (95% CI: 47%-59%) for those without, and there was significant effect measure modification by the presence of underlying conditions (P = .04). VE was lowest among children with respiratory conditions (31%, 95% CI: 19%-42%).
CONCLUSION: Influenza vaccination provided protection in both children with and children without underlying conditions. Efforts to improve influenza vaccination coverage and to initiate early treatment for influenza, particularly in populations at increased risk for severe influenza, are essential to reducing influenza-associated complications.
Journal Title
Pediatrics
Volume
157
Issue
2
MeSH Keywords
Humans; Influenza Vaccines; Influenza, Human; Child; Child, Preschool; Adolescent; Male; Female; Infant; Vaccine Efficacy; United States; Hospitalization; Emergency Service, Hospital; Vaccination
PubMed ID
41506521
Keywords
Influenza Vaccines; Human Influenza; Vaccine Efficacy; United States; Hospitalization; Hospital Emergency Service; Vaccination
Recommended Citation
Hayek H, Noble EK, Stewart LS, et al. Influenza Vaccine Effectiveness Among Children With and Without Underlying Conditions. Pediatrics. 2026;157(2):e2025072184. doi:10.1542/peds.2025-072184
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