Flu activity continues to remain elevated across the United States, according to newly released data from the Centers for Disease Control and Prevention.
The CDC estimates there have been at least 18 million illnesses, 230,000 hospitalizations and 9,300 deaths from flu so far this season.
Currently, 14 states are seeing “very high” levels of flu-like illnesses while 19 states are seeing “high” levels, CDC data shows.
Flu activity continues to climb in US with at least 15 million cases: CDC
At least 15 flu-associated deaths were reported among children for the week ending Jan. 10 for a total of 32 pediatric deaths this season. Last season saw a record-breaking 289 children die from flu, the highest since the CDC began tracking in 2004.
There is a lag in reporting of pediatric deaths and the number of deaths is likely undercounted, according to the CDC.
The CDC says that among children who were eligible for the flu vaccine and with known vaccination status, 90% of pediatric deaths this season were among children not fully vaccinated against influenza.
Guido Mieth/STOCK PHOTO/Getty Images – PHOTO: Stock image of a sick person.
About 18.6% of tests returned positive for flu during the week ending Jan. 10, which is a downward trend, according to the CDC.
Also trending downward is the share of visits to a health care provider for respiratory illnesses, which was 5.3% during the same week.
Data shows that the majority of this season’s cases are linked to a new flu strain called subclade K — a variant of the H3N2 virus, which is itself a subtype of influenza A.
Subclade K has been circulating since the summer in other countries and was a main driver of a spike in flu cases in Canada, Japan and the U.K.
Of the 547 samples of H3N2 tested since Sept. 28 that underwent further testing, more than 90% were subclade K, CDC data shows.
New York reports record-breaking number of flu hospitalizations in a single week
“Given what we’ve seen in our system and what I’ve heard from local providers, this kind of aligns with what many of us know about what’s in the community right now,” Dr. Aaron Milstone, pediatric director of infection prevention at Johns Hopkins Health System, told ABC News. “We know that flu is here, and it’s intense right now.”
CDC data shows that the majority of doctors’ visits were among those under age 24, and particularly among those aged 4 and under.
Milstone said this isn’t surprising because children are a “reservoir” for the spread of respiratory diseases.
“They’re in lots of communities where it’s easy for viruses to get shared, like schools, daycares, play dates,” he said. “There can be a lag [in data], because then you have all these kids going to visit their loved ones and grandparents over the holidays.”
The CDC said that despite some flu activity trends showing stability or a decline for two consecutive weeks, the agency will be monitoring for a second period of increased flu activity that often occurs following the winter holidays.
Joe Raedle/Getty Images – PHOTO: An Influenza Vaccine is prepared for a patient at Doctor Gary M. Kramer, MD, PA’s Pediatric office on September 12, 2025, in Coral Gables, Florida.
Doctors encourage all Americans aged 6 months and older to get an annual flu vaccine. They emphasize that the shot protects against severe disease, hospitalization and death.
Recently, the CDC changed the childhood immunization schedule with the agency no longer universally recommending the flu vaccine for children and adolescents, and encouraging parents to speak to their health care provider about the vaccine.
“We’re still in the thick of flu season, so it’s not too late to get your flu shot,” Milstone said. “So anyone who hasn’t been vaccinated, even if you’ve had flu, might still get protection from getting the vaccine.”
He said even if a person gets the flu after getting the vaccine, they are likely to be less severely ill than someone who got the flu and is unvaccinated.
“The goal of the flu vaccine is really to keep people out of the hospital and to keep them alive,” Milstone said. “I’s not 100% effective at preventing you from getting the infection, but hopefully it’s going to prevent you from getting a complication that will land you in the hospital or having one of the rare unfortunate outcomes of dying from flu.”
ABC News’ Youri Benadjaoud contributed to this report.
