Like all influenza viruses, swine flu viruses change constantly. Pigs can be infected by avian influenza and human influenza viruses as well as swine influenza viruses. When influenza viruses from different species infect pigs, the viruses can reassort
Learn more about swine flu at
http://swinefluvirus-h1n1.blogspot.com/ (http://swinefluvirus-h1n1.blogspot.com/)