... an intestinal virus change to that of a respiratory airborne-virus that is adapted to the mammalian lung? Second, the viruses must adapt to environmental changes, able to withstand temperate, ... infects mammalian hosts. These animals, usually pigs, act as a transformer or converters; creating a strain that can more readily infect humans. Pigs can be infected with both avian and human influenza ... infects mammalian hosts. These animals, usually pigs, act as a transformer or converters; creating a strain that can more readily infect humans. Therefore swine can be infected with both avian and...