... poultry, using existing vaccines effective against currently circulating human influenza strains, can reduce the likelihood of coinfection of humans with avian and influenza strains, and thus reduce ... cycle of influenza virus (Levine, 1992) Influenza pandemic and its impact Influenza viruses can change in two different ways — Antigenic drift, the HA and NA proteins of the influenza virus can ... proteins M2 protein unique NB protein unique HEF protein unique Host range Humans, swine, equine, avian, marine mammals Humans only Humans and swine Epidemiology Antigenic shift and drift; Drift...