A new flu variant, subclade K, is driving an uptick in cases across the U.S. and prolonging influenza seasons in other parts of the world.

After a sharp uptick in flu cases in mid-December 2025, flu activity across the U.S. and Canada remains high.

A ferocious surge of flu cases is linked in part to a variant that has not been dominant in the past few years — resulting in a waning of natural immunity.

The Centers for Disease Control and Prevention listed the COVID-19 delta variant as one of its "variants of concern" (VOCs) on June 15. According to the CDC, VOCs can be more contagious, more ...

A new flu strain has been detected, with the variant dubbed influenza A subclade K. How severe is the strain and does the ...

Add Yahoo as a preferred source to see more of our stories on Google. A new flu variant known as subclade K is on the rise across the country. Although a spike in this particular strain of influenza, ...

It's been less than a month since health officials reported the first known case of a new and more contagious coronavirus variant in Texas. The man, a Harris County resident, had no travel history.

SAN FRANCISCO (KGO) -- On Dec. 31, UCSF'S Dr. Charles Chiu and his colleagues were in a lab when they found what they are calling"L-452R," a California variant of COVID-19. "We actually discovered ...

The arrival of agriculture coincided with a sharp rise in a gene variant that protected against the virus that causes winter vomiting, researchers from Karolinska Institutet and Linköping University ...