Trials of a vaccine that could protect against Covid-19 are to begin in the UK.
Work on the vaccine, developed by clinical teams at the University of Oxford's Jenner Institute and Oxford Vaccine Group, began in January.
Now a study involving up to 510 healthy volunteers between 18 and 55 is to get under way.
The UK now joins only the US - with two studies - and China in beginning human trials.
Professor Saul Faust, director of the NIHR Southampton Clinical Research Facility at University Hospital Southampton, said: "There are not currently any licensed vaccines or specific treatments for Covid-19 but vaccines are the most effective way of controlling outbreaks and the international community has stepped up efforts towards developing one.
"This vaccine aims to turn the virus' most potent weapon, its spikes, against it - raising antibodies that stick to them allowing the immune system to lock on to and destroy the virus."
It is called ChAdOx1 nCoV-19 and is made from a weakened version of a common cold virus (adenovirus) from chimpanzees that has been genetically changed so it is impossible for it to grow in humans.
This has been combined with genes that make proteins from the Covid-19 virus (SARS-CoV-2) called spike glycoprotein, which play an essential role in the infection pathway of the SARS-CoV-2 virus.
Some 187 of the study participants are to be recruited in Southampton.
Prof Faust added: "We are really pleased to be supporting our colleagues in Oxford by collaborating on this extremely important study, which is one of only four vaccine trials underway worldwide and could pave the way for a vaccine to be delivered later this year.
"This study will enable us to assess if healthy people can be protected from Covid-19 with this new vaccine and it will also give us valuable information on its safety and ability to generate good immune responses against the virus."
According to the World Health Organization, more than 70 Covid-19 vaccines are in development worldwide but the UK now joins only the United States - two studies - and China in beginning human trials.
The study is taking place in Oxford and Southampton, with three further sites likely to be added.
Half of volunteers in the study will receive either the Covid-19 vaccine and the other half will be given a licensed "control" vaccine against meningitis and sepsis (the conjugate MenACWY vaccine) as comparison.
Production has already been scaled up pre-trial to prepare as early as possible for larger trials and potential future deployment.
Prof Faust, who is a consultant in immunology and infectious diseases, said: "By starting vaccine manufacturing scale-up immediately, the team can ensure that enough vaccine doses are available as soon as possible for the next trials which will include older people and children.
"Those joining the trial will be playing a critical role in the global search for a vaccine that protects us all, not least front-line NHS workers, the elderly and those with underlying health conditions."
Meanwhile, more than 30 studies are under way in France - of a world total of 860 - in search of drugs to treat the Covid-19 disease, infectologist Florence Ader said.
The research is "extremely active" in France involving some 1,600 patients, Ms Ader told a news conference.
She heads up a study dubbed Discovery in collaboration with several other European countries, with researchers conducting clinical trials of four potential treatments including the controversial hydroxychloroquine.
Of some 3,200 patients in Europe, at least 800 are in France. All are in hospital and severely ill with Covid-19.
Around the world some 150 projects seek to develop a vaccine against the novel coronavirus. France's prestigious Institut Pasteur will carry out trials on humans by this summer, Ms Ader said.