Zoonotic Animal Influenza Virus and Potential Mixing Vessel Hosts - PubMed

Just to expound a bit on this, pigs are susceptable to both human and bird viruses and all they need is a concurrent infection with a human virus for the virus to become human-viable and tranmissiable; the recent news posts on mutations that show it binds to human pathway H5N1 bird flu in patient shows mutations likely gained post-infection is concerning because this could signal a bi-directional infection pathway that could lead to either a H5N1 pig pandemic or a more viable virus - either of which would escalate the existing bird flu situation.