Promising Antibody Fights Lethal Viruses

Abstract

LITTLE MORE THAN A DECADE AGO, Nipah virus was not even a blip on the world’s infectious diseases radar. But all that changed in 1999. Nipah emerged as a newly discovered pathogen in a Malaysian outbreak of viral encephalitis among pigs and pig farmers that claimed 105 human lives. Nipahanditscloserelative,Hendravirus,stillaresomewhatobscureorganisms. But their highly pathogenic nature— Nipah’shumanmortalityratereaches75% and,insmalloutbreaks,hasbeen100%— has put researchers on a fast track to developatherapeuticagentcapableof treating infection with both viruses. In October, researchers working collaboratively in the United States and Australia announced a major step forward in combating these viruses. They demonstrated for the first time that a neutralizing human monoclonal antibody known as m102.4 is capable of protecting against disease in ferrets when given 10 hours after exposure to Nipah virus (Bossart KN et al. PloS Pathog. 2009;5[10]:e1000642). The findings have bolstered hopes that safe, effective postexposure treatment for use in humans infected with Nipah or Hendra virus can be developed. “We’ve been working with this monoclonal for years,” said Christopher Broder, PhD, professor of microbiology at the Uniformed Services University of the Health Sciences in Bethesda, Md, and a study coauthor. “It’s cross-reactive, it neutralizes all known isolates of Nipah and Hendra, and it’s fully human.” The ferret studies were conducted at the Commonwealth Scientific and Industrial Research Organization’s Australian Animal Health Laboratory, a biosecurity facility inGeelong,Victoria,Australia. Of 8 ferrets inoculated with doses of Nipah virus 10 times higher than the minimum needed to cause infection, 6 received m102.4—3 got the antibody 24 hours before inoculation and 3 received it 10 hours afterward.