London-listed pharmaceuticals company GlaxoKlineSmith will start clinical safety trials for its experimental Ebola vaccine in the U.S. as early as next week, sources told news agencies Reuters and Bloomberg.

The current Ebola outbreak in West Africa has claimed the lives of 1,427 people, according to figures reported by Bloomberg, and the death toll could exceed that of all previous Ebola outbreaks combined.

The National Institute of Health has received approval from the U.S. Food and Drug Administration (FDA) to start the Phase 1 trial, Michael Kurilla, director of the Office of Biodefense, Research Resources and Translational Research, told Bloomberg on Wednesday.

According to Kurilla, health authorities are mulling the possibility of giving the vaccine to people at risk in the region, but researchers may need to study the vaccine in humans for about a month to determine its effect.

"Exactly how all that will be done is yet to be seen and is a topic of a number of conference calls every day," he added.

Iowa-based NewLink Genetics Corp. is also understood to be is working on an Ebola vaccine, which is at a stage to begin pre-clinical trials.

Other treatments include Mapp Biopharmaceutical's ZMapp, which was used successfully to treat U.S. health workers Kent Brantly and Nancy Writebol. San Diego-based Mapp has said that their ZMapp supply is currently exhausted.