Page 28 of articles about biosecurity

Origin of H1N1pdm

The role of pigs in the generation of new strains of influenza

Pigs can act as a source of new influenza strains with zoonotic potential, but the increase of the genetic diversity of the swine influenza viruses is largely due to the introduction of influenza strains of human origin. Therefore, it is highly recommended that all staff that has frequent contact with pigs should be vaccinated against influenza.