An experimental monoclonal antibody developed at the U.S. National Institutes of Health (NIH) prevented malaria for up to nine months in volunteers exposed to the disease-causing parasite in a small trial, researchers reported on Wednesday in the New England Journal of Medicine. Malaria is a preventable disease caused by parasites transmitted to people through bites from infected mosquitoes. According to the World Health Organization, malaria caused an estimated 409,000 deaths worldwide in 2019, with 67 percent being children under 5. The only licensed malaria vaccine, Mosquirix, developed by GlaxoSmithKline, is around 30 percent effective. NIH’s early-stage study, which enrolled 40 healthy adults, tested whether a monoclonal antibody called CIS43LS could safely provide a high level of protection from malaria following controlled exposure to mosquitoes carrying the disease-causing Plasmodium falciparum parasite. Fifteen volunteers were exposed to bites from the mosquitoes. None of the nine who received CIS43LS developed malaria, compared with five …