Influenza A virus is a major public health threat, killing more than 30,000 people per year in the USA. The virus has one of sixteen possible hemagglutinin (HA) surface proteins and one of nine possible neuraminidase (NA) surface proteins. In early 2009, a novel H1N1 swine-origin influenza (S-OIV) A virus was identified in specimens obtained from patients in Mexico and the United States. The genetic make-up of this swine flu virus is unlike any other: it is an H1N1 strain that combines a triple assortment first identified in 1998 including human, swine, and avian influenza with two new pig H3N2 virus genes from Eurasia, themselves of recent human origin. One of the less studied proteins encoded by, but not incorporated in, the influenza virus is the nonstructural protein (NS) 1. NS1 counters cellular antiviral activities and acts as a virulence factor. It can bind to double-stranded RNA and sequester it from 2’-5’ OAS, preventing the activation of the RNAse L, which normally acts to degrade RNA and prevent virus replication. NS1 also binds to and inhibits the antiviral protein kinase PKR.