In a strain of mice that normally only has about a 10 percent survival rate after West Nile infection, scientists found that single doses of the antibodies given soon after infection could boost survival rates to 90 percent or higher.
"To our knowledge, these experiments are the first successful demonstration of the use of a humanized antibody as a post-exposure therapy against a viral disease," says senior investigator Michael Diamond, M.D., Ph.D., assistant professor of molecular microbiology, pathology and immunology and of medicine. "They also suggest antibody-based therapeutics may have a broader utility against other infectious diseases." Diamond points out that Macrogenics Inc., of Rockville, Md., a company that contributed to the study and licensed the antibody from Washington University, must complete other preliminary studies before the antibody can be tested in humans. But he and his colleagues are excited both by the apparent potency of the antibody and its potential to help them explore new possibilities for treating related viruses that are more prolific causes of human disease and death.
"We could give a single dose of this antibody to mice as long as five days after infection, when West Nile virus had entered the brain, and it could still cure them," says Diamond. "It also completely protected against death from the disease."
Diamond and his colleagues will report their results in the May issue of Nature Medicine.
In 2004, West Nile virus reportedly caused 2,470 infections and 88 deaths in the United States. The mosquito-borne virus, first isolated in Africa
Contact: Michael C. Purdy
Washington University School of Medicine