An experimental vaccine for Ebola is due to be put through human trials. It is said to have performed well in tests on primates.

The current outbreak in West Africa, the worst yet, has led researchers to step up their work to find medical treatments.

An experimental drug, ZMapp - a cocktail of antibodies - has already been used on seven patients, two of whom have died.

Correction 3 September 2014: The video on this page has been removed and the text amended because of an error conflating ZMapp with the new vaccine.