Scientists have discovered an antibody that neutralizes two viruses classified as henipaviruses. Nipah virus (NiV) and Hendra virus (HeV) are highly infectious agents that transitioned from infecting flying foxes in the mid-1990s to causing fatal disease in humans and livestock in Australia, Bangladesh, India, Malaysia, and Singapore. Recent outbreaks have resulted in encephalitis and acute respiratory distress, person-to-person transmission, and up to 70 percent fatality rates.