A more severe and highly contagious new strain of the flu is circulating this season. It's called subclade K, or more ...

A variant of influenza A, H3N2, is spreading across the U.S., with low vaccination rates contributing to infection rates.

A new strain of the flu is causing concerns for the rest of the winter season. The new strain, called subclade K, has made its way to the U.S. after spreading quickly through countries such as the UK, ...

* The new H3N2 subclade K strain carries seven mutations and spreads rapidly * Flu cases are rising slowly in the U.S., especially among children * The current vaccine still //offers strong protection ...