Winnipeg-tested Ebola vaccine cured monkeys of virus: Study
An Ebola drug tested in Winnipeg has been used to successfully cure 18 monkeys infected with the disease.
The experimental vaccine, called ZMapp, has already been used on seven people infected with the virus, including two American aid workers who have recovered.
According to a study published Friday in the journal Nature, researchers from the Public Health Agency of Canada collaborated with U.S. researchers starting in 2011 to create “the ultimate and the best cocktail” of antibodies to fight the deadly virus.
Both teams of researchers had come up with their own drugs, but when they combined their efforts, they developed a new drug that worked on the rhesus macaques monkey up to five days after they were infected with Ebola.
Previously, the last known drug to cure Ebola 100% had to be administered within 60 minutes of infection researcher Gary Kobinger said.
“What’s quite remarkable to us is that we could rescue animals that were quite advanced,” Kobinger told a teleconference. “The level of improvement was beyond my own expectations.”
The drugs were given to the 18 macaques either on Day 3, 4 or 5 after the animals were infected. By day five, all the macaques were showing symptoms of Ebola.
The animals were given three doses of the drug over a nine-day period.
All of the animals survived and Kobinger said there does not appear to be any side effects to the drugs.
While the drug has been successful in some human cases, Kobinger said mass production of it is still months away. Researchers plan to conduct the first clinical trial on humans early next year. They should know by next summer if those results are favourable, and then Canadian authorities would permit the manufacturer to stockpile some of the drug for compassionate use in outbreaks, but more studies would be needed before it could be widely used.
On Thursday, the World Health Organization said more than 3,000 people in Guinea, Liberia, Nigeria, and Sierra Leone have become infected with Ebola, resulting in 1,552 deaths. The outbreak continues to accelerate with more than 40% of the total number of cases having occurred within the past month.
“There is a movement to produce more” of the drug, Kobinger said, but added he does not know how that will move forward. The manufacturer is expected to be able to produce 20 to 40 doses a month.
While study “strongly supports” the concept the vaccine could be used to cure Ebola in humans, the problem with going ahead with the drug now is that the seven patients given MZapp were not involved in any clinical trials and researchers do not have all the information about how much of the drug was given to each patient, when it was administered and what other factors may have been at play. They need to do the research to prove the drug works and is safe for humans.
“It’s very speculative at this point,” Kobinger said. “How this translates to humans is very complicated.”