A total of 72 healthy adults began taking part in the trials on Tuesday.
The vaccine trials, expected to be completed by the end of January, include a ''prime'' vaccination to stimulate the immune system, followed by a second boost one or two months later, using drugs developed by pharmaceutical companies Danish Bavarian Nordic and Johnson & Johnson of the U.S.
Additional clinical studies are scheduled to start in the United States later in January and will be followed by studies in Africa, Johnson & Johnson officials said.
The vaccine trial is the third such test to be carried out on humans after two other experimental vaccines produced by GlaxoSmithKline and Newlink-Merck were administered.
The announcement came a day after Newlink-Merck resumed an experimental trial of the Ebola vaccine using a lower dosage after it halted tests at a hospital in Geneva, Switzerland, last month after four volunteers complained of suffering joint pains.
Johnson & Johnson said it has produced enough vaccine to treat more than 400,000 people in large-scale clinical trials scheduled to be conducted by April 2015.
A total of 2 million doses will be available through the course of the year, it said.
The London School of Hygiene and Tropical Medicine has reported that, in order to bring the Ebola epidemic under control, between 100,000 and 12 million doses would be needed to protect frontline workers in the three most-affected African countries.
“Through the unprecedented collaboration among the global health community, our goal is to bring this vaccine to families and frontline healthcare professionals as fast as possible,” said Paul Stoffels, Johnson & Johnson's Chief Scientific Officer and Worldwide Chairman.
Profit concerns raised
Impoverished countries including Liberia, Sierra Leone and Guinea have been mainly hit by Ebola, with 20,656 cases being confirmed by the WHO.
But, as the deadly virus has been killing people in Africa since 1979 according to WHO, medical professionals and experts have questioned why clinicians had not produced any vaccines or cures up until now, despite years of research.
Some critics have raised concerns that pharmaceutical companies may have refrained from producing Ebola vaccines until their profits were assured.
''A profit-driven industry does not invest in products for markets that cannot pay,'' Margaret Chan, Director General of the World Health Organization, said in a speech on October 13, 2014.
Johnson & Johnson said it was seeking to share the financial risk of the vaccine and development clinical trial costs by pursuing governmental and non-governmental funding sources, without specifying the costs.