Hopes of a breakthrough in the fight against Ebola have been raised by the 100 per cent successful treatment of monkeys with the deadly disease.
The experimental drug ZMapp cured the animals even when administered five days after infection, while they were displaying severe symptoms.
All 18 rhesus macaques made a complete recovery, in contrast to three other untreated monkeys that quickly fell seriously ill and died.
ZMapp is a blend of three laboratory-made antibodies designed to neutralise the virus.
Two U.S. 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.