The mid-stage, or Phase II, trials are designed primarily to test the vaccines’ safety, but will also assess whether they provoke an immune response against the deadly virus.
The development of the prime-boost and other vaccines was accelerated in response to vast outbreaks of ebola in West Africa, where at least 11,200 people have died so far in Guinea, Sierra Leone and Liberia.
“The current ebola outbreak has reinforced that speed of response is crucial,” said Egeruan Babatunde Imoukhuede, who is co-ordinating one of the trials in Senegal.
“Outbreak diseases spread quickly, so any vaccination approach must be able to keep up.”
Data from the World Health Organisation show there were 30 confirmed cases of ebola in West Africa in the week to July 5 while in Liberia, which had been declared ebola-free in May, a sixth new case was confirmed on Tuesday in a new wave of the outbreak.