Fig. 1
From: Are pigs overestimated as a source of zoonotic influenza viruses?
Schematic presentation of putative “mixing vessel” host species (pigs, quails, turkeys, humans) which express sialic acid receptors for both avian- and human-adapted influenza A viruses (IAV) in their respiratory tracts. Hence, they are considered susceptible for a wider range of IAV of different host origins. Co-infections with different IAV create reassortment opportunities increasing the likelihood of the formation of reassortants with increased zoonotic or pre-pandemic propensity