2024-25 Saw The Most US Kids Dying From Flu Since The Swine Flu Pandemic

This marks the worst season for child mortality since records of pediatric flu deaths began in 2004 – except, that is, for the H1N1 “swine flu” pandemic of 2009, when 288 deaths were recorded.

The median age at time of death among the 280 children was 7 years, with 61 percent of the deaths occurring in under-9s. Young children, particularly those under 5, are at greater risk of complications from seasonal flu like pneumonia, dehydration, and worsening of other long-term health problems they may be experiencing. Just over half (56 percent) of the children who died in the 2024-25 season had an underlying medical condition.

Most of the deaths (86 percent) were attributed to influenza A viruses. Influenza A generally causes a more severe infection. Subtypes of this virus, like H5N1 and H1N1, may infect animals as well as humans and are usually the culprits behind flu pandemics. Influenza B only causes human disease. 

Each year, a different combination of flu viruses will be most prevalent, as it’s very good at mutating and switching up the different subtypes. That’s why the vaccine must be updated every year. The current vaccines on offer in the USA are all trivalent, meaning they protect against three specific subtypes of flu. 

For the 208 children for whom this information was available, 89 percent were not fully vaccinated against the flu. We’ve seen some shake-ups in vaccine policy in the United States, but the recommendation on who should get a flu vaccine has remained consistent: everyone over the age of 6 months who is able to receive one should do so. The best time is right now, before the end of October. 

The American Academy of Pediatrics (AAP) explains that both a flu shot and a nasal spray vaccine are available for children. Individual health circumstances may mean one is more suitable than the other, but it’s best to seek guidance from your pediatrician, who will have access to your child’s medical records. 

The AAP also says vaccination shouldn’t be delayed to hold out for a specific type of vaccine, including a thimerosal-free formulation. The controversial preservative has once again been at the center of debates, but there’s no good evidence that it causes any harm. Catching the flu, on the other hand, we know is dangerous. 

Babies under 6 months are too young to receive a vaccine, and other kids may be counted out due to medical conditions. That’s another reason why getting vaccinated is so important for those who can, as it helps protect other vulnerable members of the community too. 

While it was a particularly harsh year for pediatric deaths, 2024-25’s flu season was a bad one all round.

“According to a preliminary assessment, the 2024–25 influenza season has been associated with at least 43 million illnesses, 560,000 hospitalizations, and 38,000 deaths, and was the first high-severity season since the 2017–18 season,” write the study authors, from the Influenza Division of the CDC’s National Center for Immunization and Respiratory Diseases.

It’s unclear exactly what was behind the higher mortality rate, but the authors suggest that further relaxing of COVID-era precautions as well as high co-circulation of two influenza A subtypes could be at fault. 

With the 2025-26 season fast approaching, the message from experts remains that vaccination is the best way to prevent serious illness and death from flu.

The study is published in the CDC’s Morbidity and Mortality Weekly Report.