An Ebola vaccine developed in record time has proved highly effective against the deadly virus in a large trial in Guinea and could now be used to help end a vast outbreak in West Africa.
The trial results tested Merck and New Link Genetics' vaccine on more than 4,000 people.
The people tested had been in close contact with a confirmed Ebola case, showed it gave 100% protection after ten days in those immunised.
Publishing the results online in the medical journal The Lancet today, researchers said they showed that the vaccine could be "highly efficacious in preventing Ebola virus disease".
Jeremy Farrar, a leading infectious disease specialist and director of the Wellcome Trust, which helped fund the trial, described the results as "remarkable".
"This trial dared to use a highly innovative and pragmatic design, which allowed the team in Guinea to assess this vaccine in the middle of an epidemic," he said in a statement.
"Our hope is that this vaccine will now help bring this epidemic to an end and be available for the inevitable future Ebola epidemics."
Medical director of Doctors without Borders Bertrand Draguez, which has led the fight against Ebola in West Africa, said: "For the first time there is a prospect of a tool that could protect lives and break chains of transmission."
More than 11,200 people have died from Ebola since the epidemic began in Guinea in December 2013.
This and other vaccine trials were fast-tracked with enormous international effort as researchers raced to be able to test potential therapies and vaccines whilst the virus was still circulating.
Director of Médecins Sans Frontières Ireland Jane Ann McKenna has said that has described the development of an Ebola vaccine with a 100% success rate at trials, as very encouraging news.
Speaking on RTÉ's Drivetime, Jane Ann McKenna said there are still 20-30 new cases of Ebola every week across Sierra Leone and Guinea.
Ms McKenna said that volunteers were encouraged by the earlier trials on healthy patients.
"As we were essentially testing this vaccine on healthy people, we were able to get informed consent from all the volunteers that were willing to participate on this trial.
"And I think that the direct effect that people were able to see on the ground of their family members, of their co-workers, of their neighbours essentially were actually really encouraged by this and willing to participate in the trial."
