CDC labels 2025–26 flu season ‘moderately severe’ as estimated U.S. cases reach 11 million

U.S. flu activity has remained elevated into the winter, with the Centers for Disease Control and Prevention describing the 2025–26 influenza season as “moderately severe” and warning that transmission is likely to persist for several more weeks.

According to CDC estimates cited in a Reuters report, the season’s impact had already reached at least 11 million illnesses, about 120,000 hospitalizations, and roughly 5,000 deaths at the time of the update. The numbers underline how quickly seasonal influenza can become a major strain on clinics and hospitals during peak winter weeks.

Public health experts attributed the rise to multiple factors, including holiday travel and low vaccination uptake, which can accelerate spread when families gather indoors and people return to school and work after major holidays. Misinformation about vaccines and illness risk was also cited as contributing to lower immunization levels.

The dominant strain this season has been Influenza A(H3N2), according to the same report, a subtype often associated with heavier seasonal burdens. When one strain predominates, it can shape not only clinical severity but also how well vaccines match circulating viruses.

With flu expected to continue circulating, health officials continue to emphasize practical steps: vaccination for those not yet immunized, staying home when sick, and using layered protections in higher-risk settings such as healthcare facilities and long-term care environments.

The broader message from the CDC’s classification is straightforward: the season is already significant and may not have reached its end. Communities should expect ongoing cases and pressure on local healthcare resources as winter continues.