March 20 (UPI) -- A human antibody that protected mice from a deadly malaria parasite has been discovered, and may lead to possible short-term protection and a vaccine.
Scientists with the National Institute of Allergy and Infectious Disease led research at the Fred Hutchinson Cancer Research Center in Seattle. Their findings were published Monday in Nature Medicine.
Malaria causes about 430,000 deaths each year, mainly young children in sub-Saharan Africa, according to the National Institutes of Health, which runs the NIAID. There is no highly effective and long-lasting to prevent the mosquito-borne disease.
"Development of a highly effective vaccine or antibodies for the prevention and ultimately elimination of malaria is urgently needed," the researchers wrote in the study.
Researchers isolated an antibody, called CIS43, from the blood of a mouse, which had received an experimental vaccine based on a type of whole, weakened malaria parasites called Plasmodium falciparum.
Then, the mouse was exposed to infectious malaria-carrying mosquitoes -- and was not infected.
In another mouse, CIS43 was highly effective at preventing malaria infection, the researchers report.
Researchers found CIS43 works by binding to a specific area of a key parasite surface protein. It occurs only once along the length of the surface protein. The CIS43-binding epitope also is conserved across 99.8 percent of all known strains of P. falciparum, which makes it good target for malaria vaccines to produce the neutralizing antibody.
"The demonstration that CIS43 is highly effective for passive prevention of malaria has potential application for use in travelers, military personnel and elimination campaigns and identifies a new and conserved site of vulnerability on PfCSP for next-generation rational vaccine design," the researchers wrote.
In the next step, researchers at the NIAID Vaccine Research Center want a controlled human malaria infection trial.