Flu Shots

The influenza vaccine, also known as a flu shot, is an annual vaccine to protect against the highly variable influenza virus.[1] Each injected seasonal influenza vaccine contains three influenza viruses: one influenza type A subtype H3N2 virus strain, one influenza type A subtype H1N1 (seasonal) virus strain, and one influenza type B virus strain.[2] A quadrivalent flu vaccine administered by nasal mist was approved by the U.S. Food and Drug Administration (FDA) in March 2012.