Ebola has wiped out a third of the world's gorillas and chimpanzees

Ebola is currently the single greatest threat to the survival of gorillas and chimpanzees, having killed off a third of their populations since the 1990s.

The virus is even more deadly to great apes that it is for humans, with mortality rates as high as 95% for gorillas and 77% for chimpanzees. That compares to around 50% for humans.

The outbreaks are infrequent, but when they strike they can wipe out huge swathes of the animals, especially if the carcasses are left uncollected.

In 1995, an outbreak killed off 90% of gorillas in a national park in Gabon. In 2002-2003 another outbreak killed 5,000 gorillas in the Democratic Republic of Congo.

With an estimated 100,000 gorillas left in the wild, that's a major blow.

Africa's great apes are also under attack from poaching, habitat destruction, war and other infectious diseases.

The lack of habitat means that infected animals are more likely to come into contact with each other, and therefore more likely to contract the virus; it’s a vicious cycle.

As a consequence both eastern gorillas and western gorillas have been listed as endangered since 2008.

The spread of the deadly virus could be curbed by vaccinating the animals - a safe and effective vaccine for gorillas and apes has ALREADY been developed - unlike for humans.

However, the trials of the vaccines haven’t yet involved testing vaccinated chimps with the live virus.

“Across much of Europe, medical research on great apes is either banned or highly restricted because of their cognitive similarity to humans. The question is whether or not we should make an exception in this case,” says Inglis.

Vaccinating the great apes could also help humans, since contact with infected animals has been found to cause secondary epidemics in humans.