Initial results from an Ebola vaccine trial in Guinea are "exciting" and "promising" and suggest the shot could help bring an end to West Africa's epidemic, World Health Organization director general Margaret Chan said on Friday. 

"If proven effective, this is going to be a game changer, and it will change the management of the current Ebola outbreak and future outbreaks," Chan told reporters at a news conference.

Data from a trial of an Ebola vaccine known as VSV-EBOV developed by Merck and NewLink Genetics are expected to be published later on Friday.