Over an eight-year period, the influenza vaccine demonstrated significant protection against death from respiratory illness in U.S. children, showing an 80% overall effectiveness. This protection extended to children with underlying medical conditions, with an effectiveness of 77%, and was even higher at 87% for those without pre-existing health issues.
These findings come from an analysis of data collected through the U.S. Influenza Associated Pediatric Mortality Surveillance System and survey information. Researchers examined deaths in children aged 6 months to 17 years from August 2016 to July 2025, excluding the 2020-21 flu season.
The study authors emphasized that seasonal flu vaccination is known to reduce the risk of influenza and its severe complications in children over six months old. They noted that reported influenza-associated pediatric deaths have varied widely, from 37 in the 2011-12 season to 289 in the 2024-25 season.
A notable aspect of the study is that over half of the flu-related deaths occurred in children who were otherwise healthy. Out of 1,234 child deaths attributed to the flu, 52% were in children without any underlying medical conditions.
Among children with underlying conditions, vaccination rates varied by specific health issue, being highest for those with non-asthma lung disorders (35%) and lowest for those with obesity (18%), diabetes (11%), and sickle cell disease (8%).
The analysis revealed that out of 1,086 deaths where vaccination status was known, only 23% of children with chronic conditions and 13% of those without were fully vaccinated. The proportion of flu deaths in vaccinated children each season ranged from 9% to 26%.
Vaccination coverage among children with high-risk medical conditions generally fell between 42% and 50%, while it was slightly lower for their healthy peers, ranging from 39% to 48%.
The vaccine’s effectiveness against death from influenza A was 68% and against influenza B was 77% in children with high-risk conditions. For healthy children, the vaccine was equally effective at 87% against both influenza A and B.
Furthermore, vaccine effectiveness was higher in younger children. Among those with high-risk conditions, effectiveness was 83% for ages 6 months to 4 years, compared to 66% for ages 13 to 17. Similarly, in children without underlying conditions, effectiveness was 89% for the youngest group and 80% for the oldest.
The researchers also conducted sensitivity analyses that supported the link between vaccination and protection, even after accounting for potential overestimation of vaccine coverage in survey data.
While conditions like neurological, cardiac, and pulmonary issues, as well as genetic disorders, are associated with a higher risk of flu death, the study highlights that children without these conditions represent a significant portion of flu-related pediatric fatalities.
The study’s conclusions underscore the critical role of seasonal influenza vaccination in preventing severe illness and complications of the flu in children and adolescents.
In a related commentary, medical experts from New York University Grossman School of Medicine suggested that these findings can help clinicians discuss the flu vaccine with families. They advised shifting parental expectations from the vaccine preventing all infections to its proven ability to protect against severe disease and the tragic outcome of child mortality from influenza. They also stressed the importance of robust public health infrastructure, including surveillance and vaccine registries, for accurate effectiveness analysis and targeted advocacy.
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