How bird flu viruses adapt to humans

Two new studies have identified mutations that increase the infectivity of H5N1 and H7N9 viruses through improved binding to receptors in the human respiratory tract. The findings offer much-needed strategies for monitoring the emergence of dangerous bird flu strains capable of infecting humans and for developing more effective vaccines. “Avian influenza viruses evolve rapidly, and there are many subtypes of these viruses that we need to be concerned about because, in many cases, humans do not have immunity to these newer strains,” said senior study author Ram Sasisekharan of the Singapore-MIT Alliance for Research and Technology. “Our findings can be put to use to monitor the evolution of H5N1 and H7N9 viruses in the field as well as in the clinic if and when there is an outbreak,” he added. In the past 10 years, the H5N1 virus has infected nearly 600 individuals in several outbreaks around the world, killing about 60 percent of...