Flu on the Rise: What You Need to Know About the New Variant
USASun Jan 04 2026
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The U. S. is seeing a sharp increase in flu cases, thanks to a new variant called subclade K. This variant first showed up in places like the U. K. , Japan, and Canada. The CDC reports that over half of the states are now experiencing high or very high levels of flu activity.
So far this season, there have been around 7. 5 million illnesses, 81, 000 hospitalizations, and 3, 100 deaths from the flu. This includes at least eight children. These numbers are from data up to December 20, before the holiday season kicked into full gear.
Some states are hit harder than others. For example, New York just had its worst week for flu cases since 2004, with 71, 000 cases in a single week. It's still unclear if this flu season will be as bad as last year's, but it's not too late to get a flu shot. Experts say the vaccine can still help, even if it's not a perfect match for the new variant. A study in the U. K. found that the vaccine can lower the risk of hospitalization.
The flu virus is always changing, and subclade K is a mutated version of the H3N2 strain. This strain is known for being tough, especially on older adults. The mutations in subclade K aren't enough to make it a completely new type of flu, but they are different enough to make the current vaccine less effective.
It's still too early to know if subclade K will make people sicker. Flu seasons with any version of H3N2 tend to be bad, with more infections and serious illnesses. However, it will take time to figure out if this variant spreads more easily or is just more dangerous.
The CDC says there are medicines to treat the flu, usually recommended for people at high risk of complications. These medicines need to be started within a day or two of symptoms beginning.
The CDC and major medical groups recommend a flu vaccine for everyone aged 6 months and older. Flu is especially dangerous for older adults, pregnant women, young children, and people with chronic health problems. The vaccine protects against three influenza strains, and while there's concern about the new H3N2 variant, it's still a good match against H1N1 and Type B flu.
There are different types of flu vaccines, including shots for all ages and the nasal spray FluMist for ages 2 to 49. This year, some people might be able to use FluMist at home.
