Oxford University scientists are to begin human trials of a potential coronavirus vaccine next week.
Researchers said the jab could be ready to be rolled out for emergency use by the autumn following significant progress in the early stages of development.
The Oxford team has tested the vaccine successfully on several animal species.
The World Health Organisation (WHO) has reported that more than 70 vaccines are being developed globally for Covid-19, which has infected more than two million people and killed 128,886 across the world.
However, experts have cautioned it could take at least 18 months to fully develop a jab that can be made available to millions people.
The Oxford team join three other groups of researchers – two in the United States and one in China – in beginning trials on humans.
Their project has recruited 510 people, ranging from 18 to 55 years old, to take part in the trials, said lead researcher Professor Adrian Hill.
“We are going into human trials next week. We have tested the vaccine in several different animal species,” he added.
“We have taken a fairly cautious approach, but a rapid one to assess the vaccine that we are developing.”
Professor Sarah Gilbert, a vaccinologist at Oxford, has said she is “80 per cent” confident it will be a success.
There is now hope that the jab, developed by the clinical teams at the Jenner Institute and Oxford Vaccine Group, could be ready from as early as September.
However, Professor Hill said the team must continue to increase fundraising in order to accelerate development.
“We’re a university, we have a very small in house manufacturing facility that can do dozens of doses. That’s not good enough to supply the world, obviously,” he told the BBC World Service.
“We are working with manufacturing organisations and paying them to start the process now.
“So by the time July, August, September comes – whenever this is looking good – we should have the vaccine to start deploying under emergency use recommendations.
“That’s a different approval process to commercial supply, which often takes many more years.
“There is no point in making a vaccine that you can’t scale up and may only get 100,000 doses for after a huge amount of investment.
“You need a technology that allows you to make not millions but ideally billions of doses over a year.”
The UK’s chief scientific adviser Sir Patrick Vallance has said it would be “very lucky” if a coronavirus vaccine was widely available within a year.
Sir Patrick told ITV: ”A vaccine that can be used generally – we’d be very lucky to get one within a year.”
