The United States is grappling with its most severe flu season in over a decade, as reported by Live Science. A troubling development has emerged from the Centers for Disease Control and Prevention (CDC) revealing that roughly one in eight child flu deaths this year involve brain damage. While the U.S. Food and Drug Administration's (FDA) advisory panel typically convenes around this time to determine vaccine strains for the upcoming season, this year's meeting has been postponed.
The FDA spokesperson informed Reuters on February 28 that recommendations for manufacturers would still be made public in time for updated vaccines to be available for the 2025-2026 season. Manufacturers generally rely on strains circulating in the Southern Hemisphere to predict which will circulate in the next flu season. This data helps them create vaccines targeted to those strains, ensuring maximum efficacy.
According to a CDC Morbidity and Mortality Weekly Report released on February 27, more than 19,000 people have succumbed to flu this year, including 68 children. Notably, at least nine of these children had influenza-associated encephalopathy (IAE), a condition causing brain dysfunction.
"Influenza vaccination is an important tool for preventing influenza and its associated complications,"
— The report authors
The CDC report further noted that symptoms of IAE include seizures, decreased consciousness, hallucinations, and personality changes lasting over 24 hours. Despite these findings, the CDC does not typically track IAE cases, leaving uncertainty about whether this season's numbers are unusually high.
The CDC identified that, as of February 8, nine out of 68 children who died from the flu had documented cases of IAE, constituting 13% of child fatalities. While encephalopathy refers to brain dysfunction, encephalitis involves brain swelling, according to the Cleveland Clinic.
Early data suggests that this year's flu shots have significantly reduced hospitalizations. However, experts express concern that delaying the advisory panel meeting could disrupt vaccine production, potentially leading to higher rates of serious illness and death.
The CDC has consistently recommended flu vaccinations for all eligible individuals aged six months and older as long as influenza viruses are circulating. Flu activity peaks between December and February, although it can spread year-round.
The report highlights that nervous system injuries, including IAE, are primary causes of flu-related fatalities among children. A study published in the journal Medical Science Monitor in 2021 corroborates this finding, emphasizing the critical nature of tracking and addressing these complications.
"It is not known whether cases observed in the 2024–25 season vary from expected numbers,"
— The CDC report authors
Amid these developments, the FDA remains committed to releasing strain recommendations on schedule. The agency aims to ensure that manufacturers can produce updated vaccines ready for distribution by the 2025-2026 season.
