Ebola vaccination trial success in Guinea holds hope for end to deadly outbreak of virus

The world is on the verge of being able to protect humans against the Ebola virus as a trial in Guinea finds a vaccine to have been 100 per cent effective, the World Health Organisation (WHO) has said.

Initial results from the trial, which tested Merck and NewLink Genetics' VSV-ZEBOV vaccine on some 4,000 people who had been in close contact with a confirmed Ebola case, showed complete protection after 10 days.

The results were described as "remarkable" and "game changing" by global health specialists.

"We believe that the world is on the verge of an efficacious Ebola vaccine," WHO vaccine expert Marie Paule Kieny said during a briefing in Geneva.

The vaccine could now be used to help end the worst recorded outbreak of Ebola, which has killed more than 11,200 people in West Africa since it began in December 2013.

WHO director-general Margaret Chan said the results would "change the management of the current Ebola outbreak and future outbreaks".

The Gavi Alliance, which buys vaccines in bulk for poor countries who struggle to afford them, immediately said it would back an Ebola shot once it was approved.

"These communities need an effective vaccine sooner rather than later," Gavi chief executive Seth Berkley said.

"We need to be ready to act wherever the virus is a threat."

This and other vaccine trials had been fast-tracked with huge international effort as researchers raced to test potential therapies and vaccines while the virus was still circulating.

"It was a race against time and the trial had to be implemented under the most challenging circumstances," said John-Arne Rottingen of Norway's Institute of Public Health, chair of the trial's steering group.