WASHINGTON — Flu activity has been on a major upswing across the country, according to data from the Centers for Disease Control and Prevention, with hospitalizations surging and the number of illnesses thus far this season far surpassing the amount at the same time last year.
What You Need To Know
- The CDC’s weekly U.S. Influenza Surveillance Report released Tuesday showed key flu indicators, from hospitalization rates to deaths to influenza-positive lab tests, all trending up from the previous week
- Hospitalizations in particular saw a sharp rise, with the number of patients admitted with influenza nearly doubling in one week’s time, from just under 10,000 to a little less than 20,000
- Overall, the federal health agency estimates that there have been at least 7.5 million illnesses, 81,000 hospitalizations and 3,100 deaths from the flu so far in the 2025-26 season
- Much of the activity thus far, according to the CDC data, is being driven by a new strain — a variant of influenza A ,and specifically A(H3N2) — that has become known as subclade K, with some referring to it colloquially and the surge it has brought on as the “super flu”
The CDC’s weekly U.S. Influenza Surveillance Report, released Tuesday, showed key flu indicators, from hospitalization rates to deaths to influenza-positive lab tests, all trending up from the previous week.
Hospitalizations in particular saw a sharp rise, with the number of patients admitted with influenza nearly doubling in one week’s time, from just under 10,000 to a little less than 20,000.
The CDC reported five new pediatric deaths associated with the flu over the week, bringing the total number of children who have died from influenza-related illness to eight for the current season.
Overall, the federal health agency estimates that there have been at least 7.5 million illnesses, 81,000 hospitalizations and 3,100 deaths from the flu so far in the 2025-26 season.
That marks a dramatic rise compared to last year, when the CDC estimated there had been at least 3.1 million illnesses, 37,000 hospitalizations and 1,500 deaths in total at the same point in the 2024-25 season.
All three categories thus far this season are more than double what they were at the same time last year. The CDC noted in its report that “influenza activity is expected to continue for several weeks.”
Last season, hospitalizations from the flu did not reach their peak until February, which tied for the highest peak in over a decade.
Much of the activity thus far, according to the CDC data, is being driven by a new strain — a variant of influenza A, and specifically A(H3N2) — that has become known as subclade K, with some referring to it colloquially and the surge it has brought on as the “super flu.”
Of the 275 influenza A(H3N2) viruses since Sept. 28, 2025, that were collected and given extra genetic characterization, 89.5% belonged to subclade K, according to the CDC.
Meanwhile, the CDC reported the number of states seeing “high or very high” flu activity increased to 32 from 17 the week prior.
Among the states seeing the highest activity are New York, Colorado, South Carolina and Louisiana followed by New Mexico, Idaho, Michigan, New Hampshire, Massachusetts and Connecticut.
The state of New York, for instance, saw the highest number of flu cases from Dec. 14 to Dec. 20 ever recorded in a single week, its health commissioner, Dr. James McDonald, said. The 71,123 total cases for the week marked a 38% increase from the previous seven-day period.
The report from the CDC released Tuesday covered the week ending Dec. 20. The following week’s update is scheduled to be posted Monday.
The government health agency has faced uncertainty after Health and Human Services Secretary Robert F. Kennedy Jr. ousted the members of its key immunization advisory committee to replace them with his own picks, leading to changes to vaccine recommendations with more potentially on the way.
The CDC notes in its weekly update that it recommends that everyone 6 months and older receive an annual flu vaccine.
