(NEXSTAR) – The flu is spreading far and wide ... about 97% have turned up positive for influenza A. Influenza A is further divided into subtypes. You may have heard of H1N1 or H3N2 – those ...

and is "the only influenza viruses known to cause flu pandemics." There are more than 100 different Influenza A subtype combinations currently known. Influenza B viruses, however, typically change ...

Two subtypes are typically at play each flu season: influenza type A and influenza type B. Data from the Centers for Disease Control and Prevention show that seasonal flu activity continues to ...

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 ...