A POTENTIAL vaccine for Covid has proved more than 90 per cent effective in preventing the virus, developers say.

Pharmaceutical company Pfizer has announced its coronavirus vaccine candidate is more than 90 per cent effective in preventing Covid-19 during a major trial.

The firm, which is developing the mRNA-based vaccine with BioNTech, said the results were from an independent interim analysis of the results of its phase three clinical study.

“We could not have come this far without the tremendous commitment of everyone involved.”

The vaccine has been tested on 43,500 people in six countries and no safety concerns have been raised.

Downing Street welcomed the results as “promising” and said the UK will have procured 10 million doses by the end of the year to be given out if it is approved.

Dr Albert Bourla, Pfizer chairman and CEO, said: “Today is a great day for science and humanity.

"The first set of results from our phase three Covid-19 vaccine trial provides the initial evidence of our vaccine’s ability to prevent Covid-19.

“We are reaching this critical milestone in our vaccine development programme at a time when the world needs it most with infection rates setting new records, hospitals nearing over-capacity and economies struggling to reopen.

“With today’s news, we are a significant step closer to providing people around the world with a much-needed breakthrough to help bring an end to this global health crisis. We look forward to sharing additional efficacy and safety data generated from thousands of participants in the coming weeks.

“I want to thank the thousands of people who volunteered to participate in the clinical trial, our academic collaborators and investigators at the study sites, and our colleagues and collaborators around the world who are dedicating their time to this crucial endeavour."

About 12 Covid-19 vaccines around the world are currently in the final stages of testing, but Pfizer’s is the first to report any results.

The UK has secured 40 million doses in total of the vaccine.

The Prime Minister’s official spokesman said: “The results are promising and while we are optimistic of a breakthrough, we must remember there are no guarantees.”

Pfizer and BioNTech plan to apply to the US Food and Drug Administration – the US medicines regulator – by the end of the month for emergency approval to use the vaccine.