Monkeys infected with the Ebola virus have been cured by a chemical cocktail administered 24 hours after the initial exposure. The breakthrough could eventually result in a similar human treatment for this disease, which kills up to 90% of those infected.
According to the report in Nature, researchers based at the National Microbiology Laboratory in Winnipeg, Canada, administered three different antibodies to macaques monkeys infected with the Zaire virus — the deadliest strain of Ebola, and a scourge to those living in the Democratic Republic of Congo and Gabon. The concoction, named ZMAb, was given to two monkeys 24 hours after being infected, and the other two 48 hours after infection - and all four survived without side effects. One monkey that was not treated died within five days of the infection.
Gary Kobinger, a medical microbiologist working at the University of Manitoba, led the study. The results were published today in Science Translational Medicine.
The treatment works by having the antibodies slow down the replication rate of the virus in the infected monkey until its own immune system is able to kick-in and finish the job. The antibodies were derived from mice who were vaccinated with fragments of the virus. The antibodies target and neutralize a glycoprotein on the surface of the virus that allows it to enter and infect cells. Unlike other treatments, Kobinger's cocktail contains multiple antibodies that individually target different locations of the glycoprotein, making it harder for the Ebola virus to resist attack.
The antibodies themselves are being developed by a biotechnology firm based in Toronto, Canada, called Defyrus. They are working on a larger Ebola treatment called Defilovir, which, along with the antibodies, is expected to work in tandem with an antiviral gene therapy. Defyrus is hoping to test the safety of the treatment in humans in a phase I clinical trial set to begin before the end of 2014.
Thomas Bowden, a structural biologist at the Wellcome Trust Centre for Human Genetics at the University of Oxford, noted tha, "This is certainly a viable strategy, and they have only a few steps before they can go through to humans."