Medical Express A variant of the bird flu virus, collected in 2016 and no longer in circulation, was just one mutation away from being able to bind to human receptors. This finding underscores that certain bird flu strains have the potential to cross over to humans and possibly trigger a pandemic. The variant currently circulating does not yet have the ability to bind to human receptors. The two studies, published in PNAS and Nature, were led by Utrecht University researchers Robert de Vries and Geert-Jan Boons.
Viruses use receptors—molecules found on the surface of cells—to attach to and enter those cells. Different animal species have different types of receptors. So for a virus to infect humans and spread from person to person, it must first be able to bind to human receptors.