The UK's second Ebola vaccine will begin testing on thousands of west Africans within weeks, after being fast-tracked.
The trial - which began last month in Oxford - involves two different injections given weeks apart - one to prime the immune system response, and another to boost it.
Neil Walker from Oxford, who is volunteering to take part in human testing, has said he is "putting my trust in the science" despite the very small risk involved.
"It would be nice to know at the end of the study that I have contributed to getting this vaccine out in the real world," he added.
Professor Matthew Snape from Oxford University says the fact that several companies are developing vaccines is useful for the future:
Figures from the World Health Organisation show there have been over 23,000 cases in the region and nearly 10,000 deaths as a result of the latest.
Another vaccine developed at Oxford University is already undergoing trials in Africa.
