Mutated flu strain emerges, experts concerned
Posted/updated on: December 28, 2025 at 3:23 am
TYLER — As flu season picks up in the United States, health experts are concerned about a mutated flu strain that may be immune to this year’s influenza vaccine. According to our news partner KETK, a highly contagious and mutated strain of influenza A H3N2, called “subclade K,” has emerged abroad, causing surges in infections across several countries and raising concerns about a mismatch between the current flu vaccine and mutated strain.
Subclade K is already circulating in most U.S. states, according to the Global Initiative on Sharing All Influenza Data database.
“Knowing that there’s a new mutated strain out there and H3N2 generally causes more severe disease is concerning,” Dr. Robert Hopkins Jr. medical director of the National Foundation for Infectious Diseases, said.
Though influenza A is included in this year’s influenza vaccine, the mutations of subclade K could give the virus an advantage against the vaccine’s immunity.
“One strong type of H3N2 emerged that looks like it has mutations that will evade the immunity that the vaccine gives,” Andrew Pekosz, Ph.D., a virologist at the Johns Hopkins Bloomberg School of Public health said. “We think vaccine immunity won’t recognize this subclade K H3N2 virus as well.”
Pekosz warns that though the strain can affect all ages, it is especially severe among the elderly and young children.
Along with the regular flu activity of the season, the Centers for Disease Control and Prevention estimates that there been 4.6 million cases of the flu so far, with 49,000 hospitalizations and 1,900 deaths. In East Texas, several schools saw reason to close for winter break early due to illness.
According to the CDC’s “FluView” surveillance report for the week ending Dec. 13, flu infections are increasing in most parts of the country.
It is currently too early to predict the full affects of this year’s flu season, but the CDC recommends that that everyone six months or older receives their annual flu vaccine if they have not already to best prepare.
