An experimental vaccine tested on thousands of people in Guinea exposed to Ebola seems to work and might help shut down the ongoing epidemic in West Africa, according to interim results from a study published Friday.

The vaccine showed "100 percent protection against Ebola after roughly one week," in the trial, researcher Sven Trelle from the University of Bern said, according to French news agency AFP.

Hailing the results of the trial, the World Health Organization (WHO) said the international community is "on the verge of an effective Ebola vaccine," AFP reported.

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The WHO sponsored trial of the vaccine, called VSV-ZEBOV, was the first such study carried out in an area deemed high-risk for Ebola.

There is currently no licensed treatment or vaccine for Ebola, which has so far killed more than 11,000 people since the world's biggest outbreak began last year.

If proven effective, the vaccine could be "a game-changer," said Dr. Margaret Chan, Director-General of the World Health Organization, which sponsored the trial.

In some 4,000 people who received the vaccine within 10 days of being identified as an Ebola contact, there were no cases of the disease. That compared with 16 cases in more than 3,500 people who only got the shot after 10 days.

"Before the trial started, in most clusters there had been a series of Ebola cases over the weeks prior to randomisation," Dr. Marie Paule Kieny, one of the co-authors of the WHO study into the vaccine, told medical journal The Lancet. "Since the trial started, we have seen no new cases in vaccinated volunteers within 10 days of vaccination, regardless of whether vaccination was immediate or delayed."