What Adaptive Changes in Hemagglutinin and Neuraminidase are Required for Emergence of Pandemic Influenza Viruses from Their Avian Precursors? (review)
Wild ducks are the primary natural hosts for a large variety of influenza A viruses. Occasionally viruses are transmitted from this reservoir to other species and may then cause outbreaks in domestic poultry, pigs, horses, or give rise to human influenza pandemics. The interactions between the virus and cellular receptors determine virus host-range and tissue tropism. Here we give an overview of current knowledge of the interactions of influenza virus with cellular receptors at the molecular level, the role of virus receptor specificity in interspecies transmission, and discusses the parameters of the virus that make it able to lead to a new pandemic.