There is renewed hope that a coronavirus vaccine could be available by the end of the year, as another company enters the race.
Commercial pharmaceutical company Pfizer, based in Sandwich in Kent, has begun human trials in the US and Germany, while a government-backed trial is underway at the University of Oxford.
Pfizer is working alongside BioNTech, with headquarters in Germany, to test four different vaccines.
If successful, Pfizer says it is aiming to produce a million doses by the start of next year.
Despite being a commercial company, Medical Director Berkeley Phillips says they would want the vaccine to be accessible to as many people as possible.
Everything we are doing around our research and Covid-19, is a scientific and research exercise. It's not a commercial exercise at all. And so we want to make sure that, if this vaccine proves successful, we want to make sure that there is broad access globally to those people who need it, to prevent them getting this devastating Covid-19 disease."
At the moment the University of Oxford has said very little on the progress of its trial.
However AstraZeneca has said it has the capacity to manufacture one billion doses of Oxford’s potential Covid-19 vaccine and will begin supply in September.
The pharmaceutical firm said it has secured the first agreements for at least 400 million doses of the vaccine.
Tony and Katie Viney from Bicester, along with their daughter Rhiannon, who are among 1100 participants in the Oxford study, say the trial is going well.
Katie Viney says: "It's as if we've not had anything. We've had no side effects at all. We've always been hopeful right from the beginning. We know from testing and screening that the only way we're going to get back to normal is with a vaccine. Because until we have one, people are still at risk."
Elsewhere, a trial to see whether two anti-malaria drugs could prevent Covid-19 has begun in Brighton and Oxford.
More than 40,000 people who work with confirmed or suspected coronavirus patients from Europe, Africa, Asia and South America will take part in the randomised trial, testing to see if hydroxychloroquine is effective in fighting the virus.
The investigation will be led by the Bangkok-based Mahidol Oxford Tropical Medicine Research Unit (MORU), which is supported by the University of Oxford and charity Wellcome.
So far, there have been no conclusions over its safety and effectiveness on coronavirus.
The first UK participants in the new trial can be enrolled at Brighton and Sussex University Hospitals and at Oxford’s John Radcliffe Hospital.
Further testing is expected at another four sites by the end of May, with 25 total locations opened across the UK before July and more planned around the globe.
The team aims to deliver results by the end of 2020.