A new flu variant is rising rapidly. Here's what you should know

LINDSEY WASSON Associated Press ONLY about 42% of adults and children got a flu shot in 2025, the CDC said. Above, at a clinic in Seattle.

- LAURAN NEERGAARD

Flu is rising rapidly across the U.S., driven by a new variant of the virus expected to keep growing.

That variant, known as "subclade K," led to early outbreaks in the United Kingdom, Japan and Canada. On Dec. 30, the U.S. Centers for Disease Control and Prevention reported high or very high levels of illness in more than half of the states.

The CDC estimated there have been at least 7.5 million illnesses in the U.S., 81,000 hospitalizations and 3,100 deaths from flu this season. That includes at least eight child deaths, and is based on data as of Dec. 20, before major holiday gatherings.

Some states are particularly hard-hit. New York's health department said the week that ended Dec. 20 marked the most flu cases the state had recorded in a single week since 2004: 71,000.

It's far too soon to know whether this flu season will be as severe as last winter's.