Researchers in the US have confirmed that the first human trials to test the effectiveness of an experimental Ebola vaccine will be launched next week.
There is no vaccine on the market against Ebola, and global attempts to get one ready are being fast-tracked as West Africa struggles with an accelerating outbreak of the hemorrhagic virus.
The first US phase 1 trial has enrolled three volunteers so far, and begins next week at the National Institutes of Health Clinical Center.
It involves a product made by Glaxo Smith Kline and US government scientists, and is being referred to as the NIAID/GSK Ebola vaccine candidate.
"We have the green light to begin," said Anthony Fauci, director of the National Institute of Allergy and Infectious Disease (NIAID).
"The launch of phase 1 Ebola vaccine studies is a first step in developing a vaccine that could be licensed and used in the field to protect not only the front line health care workers but also those living in areas where Ebola virus exists."
The study will focus first on the safety of the vaccine against two strains of Ebola -- Sudan Ebola and the type currently spreading in West Africa, known as Zaire Ebola.
It will also look at the antibody response it elicits in people to see if it is likely to be effective.
Past studies have shown it works "extremely well" in preventing Ebola infection in primates, Fauci said.
In October, another phase 1 trial on 20 healthy adults will begin using a vaccine that prevents just one strain, Zaire Ebola.
In addition, safety trials on Ebola vaccines are also gearing up worldwide, with similar efforts set to begin soon in Britain, Mali, and the Gambia.
"A candidate Ebola vaccine could be given to healthy volunteers in the UK, the Gambia and Mali as early as September, as part of a series of safety trials of potential vaccines," a statement from the Wellcome Trust said.
There is enough funding to allow GSK to make some 10,000 extra doses of the vaccine, so that if the trials are successful, it could be made available to the World Health Organization quickly, it added.
In the meantime, the only way to prevent the spread of Ebola is to avoid close contact with the bodily fluids of infected people and those who have recently died of Ebola.
The first ever outbreak of Ebola is West Africa has swiftly grown to become the largest in history, killing 1,552 of the more than 3,000 people infected since the start of the year, according to the WHO.
Affected countries include Guinea, Sierra Leone, Liberia and Nigeria.
Fauci said the trials would not take place in these nations because they don't have the necessary infrastructure for a rigorous safety trial, while Mali and the Gambia do.
"The vaccine will come as soon as we can get that vaccine in a safe and effective way to people," Fauci told reporters.