Influenza Vaccine Effectiveness Against Pediatric Death in the United States: 2016-2025.

Background

AND

Objectives

Seasonal influenza vaccination has been shown to reduce the risk of influenza and severe complications among children aged 6 months and older. Since 2010, reported numbers of influenza-associated pediatric deaths among children younger than 18 years have ranged from 37 during the 2011 to 2012 season to 289 during the 2024 to 2025 season. We estimated influenza vaccine effectiveness (VE) against pediatric death from 2016 to 2017 through 2024 to 2025.

Methods

We conducted a case-cohort analysis comparing current season influenza vaccination status among reported influenza-associated pediatric deaths with survey estimates of influenza vaccination coverage in pediatric age groups. Underlying medical conditions and current seasonal influenza vaccination were obtained from surveillance case reports. We estimated vaccination odds ratios (OR) and 95% CIs from logistic regression comparing influenza vaccination among children who died with vaccination coverage in comparison cohorts. VE was calculated as (1 - OR) × 100.

Results

From August 2016 through July 2025, 1234 laboratory-confirmed influenza-associated pediatric deaths were reported among children aged 6 months to 17 years. Of 1086 reported deaths with influenza vaccination information, 124 (23%) of 530 children with underlying medical conditions and 70 (13%) of 556 children without known conditions were fully vaccinated against influenza. Average influenza vaccination coverage in survey cohorts was 49%. VE was 80% (95% CI 75-84) overall, 77% (95% CI 71-82) among children with underlying medical conditions and 87% (95% CI 84-89) among children without known conditions.

Conclusions

Influenza vaccination reduced risk of fatal influenza among children with or without known underlying medical conditions.