Experts said the results were ‘extremely encouraging’ and ‘better than expected, while the scientist who discovered Ebola in 1976 said it was vital to start clinical trials immediately.
“This well designed trial in non-human primates provides the most convincing evidence to date that ZMapp may be an effective treatment of Ebola infection in humans,” said Professor Peter Piot, now director of the London School of Hygiene & Tropical Medicine.
“It is now critical that human trials start as soon as possible.
“I never thought that 40 years after I encountered the first Ebola outbreak, this disease would still be taking lives on such a devastating scale.”
ZMapp is a blend of three laboratory-made antibodies designed to neutralise the virus.
Two US doctors given the drug after they were infected with Ebola while working in Liberia subsequently recovered.
But it is not known whether they were saved by the drug or just lucky. About 45 per cent of those infected in the current outbreak have survived without treatment.
At least two other patients treated with ZMapp have died, possibly because help got to them too late.
The new research, published in a special report on Nature journal’s website, provides the first evidence that the drug work in primates and can be highly effective.
A team of scientists led by Dr Gary Kobinger, from the Public Health Agency of Canada, wrote: “ZMapp exceeds the efficacy of any other therapeutics described so far, and results warrant further development of this cocktail for clinical use .
“We hope that initial safety testing in humans will be undertaken soon, preferably within the next few months, to enable the compassionate use of ZMapp as soon as possible.”
The breakthrough follows warnings from the World Health Organisation (WHO) that the Ebola outbreak in West Africa could eventually claim more than 20,000 victims.
Latest figures show 1,552 deaths from the 3,069 cases reported so far.