WASHINGTON (AP) — This year’s tough flu season, the strongest in the United States in 15 years, has led federal health authorities to try to determine whether it has triggered an uptick in a rare but potentially deadly brain complication in children.
The CDC estimates that 19,000 people have died from the flu this winter, including 86 children. The CDC said Thursday that at least nine of those minors experienced brain complications, and they asked state health departments to help investigate whether there are more cases like these.
There is some good news: the CDC also reported that this year’s flu vaccines are fairly effective at preventing flu-related hospitalizations, among about 45% of Americans who were vaccinated. But this comes one day after the Trump administration heightened the uncertainty already affecting federal health agencies, after canceling a panel of experts that was supposed to help select the vaccine formulation for next winter.
Still, it’s not too late to get vaccinated this year: “If you haven’t received the flu shot yet, do it because we are still seeing high flu activity across most of the country,” advised Dr. Sean O’Leary of the American Academy of Pediatrics.
Flu vaccine effectiveness varies from year to year. While it doesn’t do a great job blocking infections, its main role “is to keep you out of the hospital and keep you alive,” said Dr. William Schaffner, a vaccine expert at Vanderbilt University.
Preliminary CDC data released on Thursday found that children who received this year’s vaccine were between 64% and 78% less likely to be hospitalized than their unvaccinated counterparts, and adults were between 41% and 55% less likely to be hospitalized.
And what about those brain complications? This month, state health departments and hospitals warned clinicians to watch for pediatric flu patients who develop seizures, hallucinations, or other signs of “influenza-associated encephalopathy or encephalitis,” and a more severe subtype called “acute necrotizing encephalopathy.” Encephalitis is inflammation of the brain.
On Thursday, the CDC released an analysis of 1,840 child deaths from flu since 2010, finding 166 with those neurological complications. The majority were unvaccinated. But the agency concluded that it is not clear whether the nine deaths this year with those complications — four of which involved the most severe subtype — represent an uptick.
These neurological complications are not regularly tracked, making it hard to find answers. In California, Dr. Keith Van Haren of Stanford Medicine Children’s Health — a pediatric hospital and obstetrics center — said this month that doctors across the country had reported about 15 cases related to that severe subtype, and “we’re aware of more cases that may meet the criteria.” He did not say how many died.
O’Leary, from the pediatrics academy, noted that parents should remember that this complication is rare. The guidance remains to seek medical care whenever a child with flu shows unusual or worrisome symptoms, such as trouble breathing.
Doctors see more neurological complications during severe flu seasons — they can be linked to particular influenza strains — and survivors may have ongoing seizures or other lingering problems, he noted.
Meanwhile, vaccine manufacturers are already gearing up for the months-long process of crafting vaccines for next winter. An FDA advisory committee was set to meet on March 13 to help decide which flu strains to include, but after that meeting was canceled, it is unclear whether the government will decide on its own.
“Historically we’ve worked hard to achieve transparency in all these vaccine discussions,” O’Leary said, and added that it’s important for the public to understand what is weighed when deciding the composition of the flu vaccine and other vaccination recommendations.
“The FDA will publicly release its recommendations to manufacturers in time for updated vaccines to be available for the 2025-2026 influenza season,” Andrew Nixon, the HHS communications director, said in an email.
