Initial tests in monkeys showed the vaccine, developed by Janssen Pharmaceutical Companies of Johnson and Johnson, gave complete protection against Ebola.
The volunteers in Oxford are the first humans to receive the vaccine.
Dr Matthew Snape, from the Oxford Vaccine Group, part of the University of Oxford Department of Paediatrics, said: "We aim to immunise all participants within a month.
The trial involves volunteers receiving an additional booster dose one or two months after the initial injection.
Similar small trials will also get under way in the US and three African countries unaffected by Ebola.
The first dose is designed to prime the immune system with the second booster dose to enhance the immune response.
The two doses contain different components, but both include genes for a protein from the Zaire strain of the Ebola virus.
The trial organisers stress the vaccine cannot cause anyone to be infected with Ebola.
The immune response the vaccine generates - both antibodies and T cells - will be measured over the course of a year.
Johnson and Johnson said it hoped to begin a larger Phase 2 trial in Africa and Europe within three months and then to have the vaccine available for use in Liberia, Guinea and Sierra Leone by the middle of 2015.
The company says it could have 2m doses of the vaccine available this year.
