The soft palate is an important site of adaptation for transmissible influenza viruses
Efficient airborne transmission of influenza viruses between humans is associated with use of α2,6-linked sialic acids, not α2,3-linked sialic acids; however, using a loss-of-function approach in which a 2009 pandemic H1N1 influenza virus was engineered to bind α2,3 sialic acids, this study shows in ferrets that the soft palate is an important site for the switch of receptor usage to take place, and reveals that this tissue rapidly selects for transmissible influenza virus with human receptor preference.