Flu is rising rapidly, driven by a new variant. Heres what to know

Published: Wednesday, December 31, 2025 at 3:25 pm

Flu Season Surges Across the U.S. Driven by New Variant

The United States is experiencing a rapid rise in flu cases, fueled by a new variant of the virus, with further increases expected due to holiday travel. The Centers for Disease Control and Prevention (CDC) reported high or very high levels of illness in over half of the states as of December 20th.

The new variant, known as subclade K, has already caused outbreaks in the United Kingdom, Japan, and Canada. The CDC estimates that this flu season has resulted in at least 7.5 million illnesses, 81,000 hospitalizations, and 3,100 deaths, including at least eight child deaths. Some states are experiencing particularly high case numbers, with one state reporting the highest weekly flu case count since 2004.

Subclade K is a mutated version of the H3N2 strain of the Type A flu virus. While not a completely new type of flu, its mutations have made it different enough to potentially evade some of the protection offered by this year's vaccine. Preliminary analysis from the U.K. suggests the vaccine still provides partial protection, reducing the risk of hospitalization.

Health experts emphasize that it's not too late to get a flu shot, which can still prevent severe illness. The CDC recommends vaccination for everyone aged six months and older. Only about 42% of adults and children have received a flu vaccination this year. The flu is particularly dangerous for those 65 and older, pregnant women, young children, and individuals with chronic health conditions.

The CDC notes that prescription medications are available to treat the flu, especially for those at high risk of complications, but they must be started soon after symptoms appear. The current vaccines are designed to protect against three influenza strains.

BNN's Perspective:

While the emergence of a new flu variant is concerning, the availability of vaccines and antiviral treatments offers a degree of protection. It's crucial for individuals, especially those in high-risk groups, to prioritize vaccination and consult with healthcare providers if they experience flu-like symptoms. Public health messaging should continue to emphasize the importance of preventative measures and early treatment to mitigate the impact of this flu season.

Keywords: flu, influenza, subclade K, H3N2, vaccine, CDC, illness, hospitalization, deaths, variant, vaccination, symptoms, prevention, health, children, adults, travel

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