An experimental drug created in San Diego and used to treat seven Ebola victims works by binding antibodies to the top and bottom of the virus, scientists at the Scripps Research Institute reported Monday.
In a study published online in the journal Proceedings of the National Academy of Sciences, researchers using electron microscopy found that two ZMapp antibodies attach themselves to the base of the virus, appearing to keep it from entering cells.
ZMapp, made by Mapp Biopharmaceutical, was administered to the patients under emergency procedures, even though it has not been cleared for general use by federal regulators. Five of the seven patients survived, according to Scripps.
“The structural images of Ebola virus are like enemy reconnaissance,” said Erica Ollmann Saphire, a Scripps structural biologist. “They tell us exactly where to target antibodies or drugs.”
A ZMapp antibody also places itself on the top of the virus, possibly to serve as a beacon to call attention to the body’s immune system that an infection is present, Scripps reported.
The new research is among studies performed by the National Institutes of Health-funded Viral Hemorrhagic Fever Immunotherapeutic Consortium, of which Scripps is a member. The consortium is testing antibodies from 25 laboratories around the world in order to develop the best drug cocktail for neutralizing Ebola and other closely related hemorrhagic fever viruses.
The announcement from Scripps came the same day that officials at a hospital in Nebraska said a surgeon who contracted Ebola in Sierra Leone died, despite receiving ZMapp as part of his treatment.
Dr. Martin Salia, the chief medical officer and surgeon at the Kissy United Methodist Hospital in African nation’s capital of Freetown, arrived Saturday at Nebraska Medical Center in Omaha and with hardly any kidney function. His condition worsened and he died around 4 a.m. today, according to the medical center.
Salia is the second person to die of Ebola in the United States. More than 5,000 people have died of the disease in Sierra Leone, Guinea and Liberia.
Scripps said the next step for the consortium is to study antibodies from human survivors of the current outbreak. Saphire, who leads the group, hopes they can also develop a back-up cocktail in case the virus mutates and becomes resistant to treatment.
The Ebola virus has already undergone more than 300 genetic changes during the current outbreak, according to TSRI. Areas targeted by ZMapp are unaffected so far.
According to Scripps, ZMapp will undergo clinical trials early next year.
—City News Service