Many people who get flu infections experience relatively mild symptoms that can be managed at home. But serious and potentially life-threatening complications are possible, and some doctors are seeing a spike this year in severe neurological symptoms among infected children.
“Similar possible increases have been observed in other jurisdictions throughout the U.S.,” Massachusetts officials said in the February 14 report. “At this time, it is not clear why increased cases of neurological complications associated with influenza are being observed this season.”
How Flu Can Affect the Brain
The report focused on a small but rising number of children hospitalized for influenza who developed severe neurological complications such as seizures, hallucinations, reduced consciousness, nerve damage, abscesses, and swelling in the brain.
Among the most worrying complications is a condition known as influenza-associated acute necrotizing encephalopathy (ANE), according to the report. ANE is a severe form of influenza-associated encephalopathy or encephalitis (IAE), which involves serious neurological issues that result from inflammation and swelling in the brain.
From 2010 until February 8, 2025, 1,840 kids died of influenza, including 166 deaths (9 percent of cases) associated with IAE.
Cases are higher than normal this flu season, with 9 out of 68 pediatric influenza deaths (13 percent of cases) involving IAE.
Too Soon to Tell if This Flu Season Will Be Worse for Children
“We don’t know at this time whether the anecdotal reports of influenza neurological complications translates into a higher overall rate of complications, or if it ends up being similar to previous years,” says James Antoon, MD, PhD, an assistant professor of pediatrics at Vanderbilt University Medical Center in Nashville, Tennessee, who wasn’t involved in the IAE reports.
“These complications are uncommon but can be life-threatening,” Dr. Antoon says. “While neurologic complications of influenza are more common in those with underlying neurologic conditions, they can occur in otherwise healthy children as well.”
Low Flu Vaccine Uptake Could Be a Contributing Factor
If there really is a surge in severe neurological complications among kids with the flu this year, lower vaccination rates could be one reason for the increase, Antoon says.
It’s also possible that the strain of influenza circulating this year is contributing to more severe infections than strains circulating in previous years, Antoon says. But the vaccine developed this year is a good match for the currently circulating strains of influenza, Antoon adds.
“It’s possible there is something different about the influenza strains this season, or the interaction between the virus and the immune system, that could be contributing to more neurological complications,” Antoon says.
Vaccination Is the Best Way to Prevent Serious Flu Complications
Vaccination is still the best way to prevent getting the flu or experiencing serious complications, says Philip Britton, PhD, a pediatric infectious disease physician and an associate professor at the University of Sydney in Australia, who wasn’t involved in the recent IAE reports.