MEDIA RELEASE What’s in the 2010-2011 seasonal flu vaccine and why? Each year, the seasonal influenza vaccine contains three influenza viruses – one influenza A (H3N2) virus, one influenza A (H1N1) virus, and one influenza B virus. The 2009 H1N1 influenza virus strain is included in the 2010-2011 seasonal flu vaccine because scientists continue to […]