We've all heard of "the flu" but when it comes to types, subtypes and variants, influenza can get a bit complicated. According to the U.S. Centers for Disease Control and Prevention (CDC), nearly ...

In this prospective observational study, immune protection against H5N1 and H7N9 avian influenza virus (AIV ... likely primed by A(H3N2) subtype clade 2 virus. 1978-1997 (group 3 [G3]; n ...