Influenza levels in the US are the highest they've been in 15 years amid winter weather and a second wave of the virus.

The winter flu season features two types of influenza. Here's what you need to know about them and how they differ.

It's flu season, but not all influenza is the same. If you're feeling sick, it helps to know the difference between flu A and ...

The flu is spreading far and wide across the U.S. – and influenza A is largely to blame. Of all the flu tests reported to the ...

RSV, respiratory syncytial virus, usually peaks in December and January while infecting the nose, throat and lungs, usually ...

Influenza A virus particles strategically adapt their shape—to become either spheres or larger filaments—to favor their ...

While we often refer to it as "the flu," the influenza virus has several strains, with flu A and flu B considered the most ...

The United States is seeing a second peak in flu cases this season. After doctor’s office visits for flu dipped early this ...

That's the way one scientist puts it — referring to how infected wild birds survive long enough to spread it to birds and ...