Drug companies and researchers are racing against time to develop a vaccine against the novel coronavirus - Covid-19.
The United Kingdom joined the United States, China, Germany and Israeli in the search for a vaccine even as the global caseload exceeded 200,000.
While the UK is till testing mice, the US is a step ahead, having started clinical trials on humans following a presidential directive.
Scientists at the University of Cambridge say they are working "as hard and as fast as they possibly can" to find a vaccine to stop the spread of the virus.
"It's a complex process. Right now we have our vaccine candidates in mice and they're generating immune responses to the vaccine," Jonathan Heeney told the BBC at a laboratory with access so restricted he had to talk through a glass window. "We're working around the clock with a team of experts and everybody is collaborative. The sooner we can get a vaccine or therapy out there the better," said Prof Heeney.
But experts warn that it could take a year to 18 months to approve any vaccine.
In the United States, Phase One of the clinical trial began in Seattle, Washington. Four adults, the first of 45 eventual participants, on Monday received their first doses of an experimental vaccine developed through a partnership between the US National Institute of Allergy and Infectious Diseases (NIAID) and Moderna, a biotechnology company based in Cambridge, Massachusetts.
There are nearly 400 global clinical trials related to the coronavirus under way, according to the WHO.