The Center for Disease Control and Prevention (CDC) has reported that influenza is dramatically increasing across the U.S. as a new strain of the virus is circulating.
20 million cases of influenza have been reported during the first three weeks of January, resulting in 11,000 deaths, 44,000 pediatric deaths, and 270,000 hospitalizations, according to the CDC.
Dr. William Schaffner, Professor of Medicine at Vanderbilt University, told American Community Media on Feb. 5:
“It’s very difficult sometimes to distinguish the flu, certainly from other viral respiratory infections, COVID, and RSV. A simple cold usually is from the neck up. Sore throat, runny nose, maybe feeling out of sorts.”
He continued, “But if your illness begins suddenly and seriously, and you feel very bad, and if you develop a cough, those are the things that should make you think: influenza or another one of those viruses,” said Schaffner, recommending medical intervention early on for older people, children, and those who are immunocompromised.
The American Academy of Pediatrics also reported that the current flu season is labeled as “high severity” for children and teens ages 0-17.
“Of the children this year so far who have very tragically died of their influenza illness, the CDC says 90 percent never received a vaccine. That would be something that will be a burden to those parents for many years, said Schaffner. “Not that the vaccine is perfect, but it might have given those children a better chance to get over their infection.”
He went on to say that an updated vaccine was created last spring. With the onset of the current flu season this past January, one of the strains of the flu mutated and created a new strain, influenza A H3N2, therefore presenting a challenge to what was in the last vaccine.
Influenza A H3N2 is the current strain that has caused devastation among many; it has also been referred to as the “subclade K” strain.
According to the UMass Chan Medical School, cases of influenza rose quickly in October 2024, but each year, flu season varies. In comparison, the current flu season started out semi-slow, with an uptick of the flu showing across the U.S. in mid-December 2025.
Zachary Binder, MD, said in a report for UMass Chan Medical School, “Traditionally, the flu is most dangerous for people over 65 or those with underlying health conditions, with young children experiencing more mild symptoms. But this year’s strain is hitting kids harder.”
He continued, “They are arriving in the emergency room after having had a high fever of more than 104 degrees for 5-7 days, or with flu complications including febrile seizures, croup, or severe hydration.”
Binder also spoke about the flu vaccine and strongly recommends people get their flu shots sooner rather than later.
“Waiting longer would limit the window in which the vaccine is most effective. That’s because it takes a couple of weeks for the flu shot to impart its maximal benefits. Vaccination in mid-January would mean peak protection in late January and early February. Flu season generally peaks from December through February in North America.”
In a Cedar-Sinai Newsroom interview, Sam Torbati, MD, co-chair and medical director of the Cedars-Sinai Emergency Department, said the strain is very intense.
“It seems to be a more aggressive strain, and it seems to be a tougher problem. Last year, I don’t recall this many patients becoming this ill. It may get much worse.”
