US Flu Cases Hit Highest Level in 25 Years
New influenza A virus strain called subclade K dominates confirmed cases
The United States is at the highest level of respiratory illness since at least the 1997-98 flu season, according to data published Monday by the Centers for Disease Control and Prevention (CDC). The CDC estimated that at least 11 million people have had the flu this season, 120,000 have been hospitalized with it, and 5,000 people have died.
One flu-associated pediatric death occurring in the 2025-2026 season was reported to CDC this week, bringing the season total to nine reported influenza-related pediatric deaths.
During the last week of the year, 8.2% of doctor visits were for flu-like symptoms. At the same point last season, which was also a year with high flu activity, that number was 6.7%.
All but four states show high or very high levels of activity as a new virus strain called subclade K continues to spread. Subclade K is a strain of the influenza A (H3N2) virus, and influenza A has been the most frequently reported influenza viruses so far this season. In turn, among 389 influenza A (H3N2) viruses collected since Sept. 28, 2025 that underwent additional genetic characterization at the CDC, 90.5% belonged to subclade K.
When it comes to how hard the flu is hitting this year, the season has not broken any records yet, CNN reported. So far, the number of people hospitalized puts this season in third place since 2010-11, but those numbers could climb as the virus spreads. The CDC expects flu activity to continue for several weeks.
Additionally, on Monday, the U.S. dropped childhood vaccine recommendations for flu, rotavirus, meningococcal, and hepatitis A, Reuters reported. The latest rollback advances Health Secretary Robert F. Kennedy Jr.’s goal to pare back childhood vaccination, and health experts warned could lead to preventable hospitalizations and deaths.
Flu vaccinations already have been dropping in children, from a peak of 53% during the 2019-20 flu season to 42% at the same point this season. Vaccines also have dipped in adults, from nearly 61 million in 2019-20 to roughly 48 million this year, CDC data showed.

