Scientists found a link between lower levels of a particular nutrient, vitamin D, and a higher risk of severe flu. Here, ...

Flu season in the U.S. is particularly bad this year, and a new branch of the flu family tree may be to blame.

The CDC estimates there have been at least 19 million cases so far this season.

The U.S. has terminated its partnership with the World Health Organization, opting instead to work directly with other ...

Flu cases and hospitalizations are surging, already breaking last season's records. Here's where activity is highest, what ...

Flu activity continues to remain elevated across the U.S. with at least 18 million cases, according to newly released data ...

The Influenza A H3N2 virus subclade K represents a change in the basic structure of the influenza virus.

Subclade K (previously known as J.2.4.1) is gaining attention because it appears to be spreading much earlier in the flu ...

Medical experts debunk flu shot myths: vaccines use inactive virus that cannot cause illness. Discover what side effects actually mean for your immunity.

Health experts say the U.S. flu season appears to be waning with two straight weeks of decline in measures of flu activity.

Respiratory virus season is in full swing across California, with several illnesses spreading across the state. Cases of ...

There is a high number of flu cases in South Carolina, even after numbers have decreased since last week. A winter storm ...