Human tests of two possible Ebola vaccines have proven safe and efficacy tests will begin within weeks in the three west African countries ravaged by the deadly virus, the World Health Organization said Friday.
"These trials are about to begin for the two lead vaccines," WHO assistant director general Marie-Paule Kieny told reporters, adding that the vaccines would be tested on thousands of people across Guinea, Liberia and Sierra Leone.
The Phase III testing to ensure the vaccines actually protect against the virus that has killed 8,259 people in the three countries is set to begin in Liberia by the end of the month, she said.
Separate tests are scheduled to start in Sierra Leone and Guinea in February, she added.
The vaccine manufacturers must determine before then what the appropriate dosage is, she said.
There is no licensed treatment or vaccine for Ebola, and the WHO has endorsed rushing potential ones through trials in a bid to stem the epidemic.
The two potential vaccines that have been undergoing Phase 1 safety tests on humans are ChAd3, made by Britain's GlaxoSmithKline, and VSV-ZEBOV, manufactured by the Public Health Agency of Canada and licenced by US firm NewLink Genetics.
Tests of the two potential vaccines have been conducted on volunteers in a range of countries, including Switzerland, Mali, Gabon, Britain, Germany, Canada and the United States.
Johnson & Johnson meanwhile announced this week that human trials of its proposed vaccine had begun in Britain, and Kieny said the company also expected to soon be able to start efficacy trials.
Describing 2014 as the year when "the Ebola virus challenged humanity," Kieny voiced confidence that this year would be remembered as the one when "humanity used our best scientific minds to fight back."