A new form of the flu, which is highly contagious and aggressive, is sweeping the nation this season. A mutation of influenza ...

A highly contagious flu mutation called subclade K is sweeping the nation, raising health concerns about vaccine ...

Doctors and scientists say this year's influenza season could be tougher than usual, with a new version of the flu virus, ...

As flu season picks up in the United States, health experts are concerned about a mutated flu strain that may be immune to this year’s influenza vaccine. A highly ...

At least 14 states and Washington, DC, are seeing high and very high levels of flu, mainly caused by a surprise new influenza ...