Many scientists have warned that the pandemic might only be stopped with an effective vaccine, which typically takes years to develop.
In the long term, a viable vaccine could be vital for protecting the most vulnerable, enabling restrictions to be eased and helping people get back to normal life, said Robin Shattock, who is leading the vaccine research.
The vaccine uses synthetic strands of genetic code based on the virus. Once injected into the muscle, the body's own cells are instructed to make copies of a spiky protein on the coronavirus.
That should in turn trigger an immune response so that the body can fight off any future Covid-19 infection.
About a dozen vaccine candidates are currently in early stages of testing in thousands of people. There are no guarantees any will work but there's increasing hope that at least some could be ready by the end of the year.
Oxford University recently began an advanced study involving 10,000 volunteers, and the US is preparing for even larger studies in July that involve 30,000 people each testing different candidates, including Oxford's and one made by the National Institutes of Health and Moderna Inc.
Scientists have never created vaccines from scratch this fast and it's far from clear that any will ultimately prove safe and effective. Still, numerous countries, including Britain, France, Germany, the Netherlands and the US, have already placed advance orders for millions of vaccines that could be available by the end of the year if they prove to be effective.
The World Health Organization noted on Monday that there have been about 100,000 new cases reported every day for the past two weeks and that relaxed restrictions in many countries have led to a new surge of cases.