THE British government has asked its independent medicines regulator to study Pfizer/BioNTech's coronavirus vaccine for 'an imminent roll-out'.
The pharma giant and its German partner said they will ask US regulators for emergency use authorisation for the vaccine in what would be a major step towards fighting back against the global pandemic.
A recent UK study indicated individuals infected with coronavirus are unlikely to catch the illness again for at least six months.
Health secretary Matt Hancock said the government had formally asked the Medicines and Healthcare products Regulatory Agency to assess the Pfizer/BioNTech vaccine for its suitability.
If approved, the vaccine would be free "at the point of delivery" across the UK from the country's state-run National Health Service (NHS).
The service would be ready to start a mass vaccination programme next month if the MHRA gave its agreement on the jab, he told a news conference.
Britain -- one of the world's most-affected countries by the outbreak with more than 54,000 deaths from 1.4 million cases -- has ordered 40 million doses.
Researchers at the University of Oxford said its large-scale study into Covid-19 re-infection had produced promising results.
The study was launched after observations from healthcare professionals that re-infection was relatively rare.
"We can be confident that, at least in the short term, most people who get Covid-19 won't get it again," said Oxford University Professor David Eyre, one of the authors.
The authors highlighted they had not yet gathered enough data to make a judgement on re-infection after six months.
However, the ongoing study has an end goal of verifying how long protection lasts in total.
The World Health Organization (WHO) welcomed the Oxford study saying the findings extended its understanding of coronavirus protection.
"We really commend the researchers for doing those studies," WHO emergencies director Michael Ryan told reporters in Geneva, explaining the findings had delivered the "best data".
The Oxford study into re-infection drew on data from regular coronavirus testing of 12,180 health care workers at OUH over a period of 30 weeks.
It found that none of the 1,246 staff with coronavirus antibodies developed a symptomatic infection.
Three members of staff with antibodies did test positive for the virus that causes Covid-19 but were all well and did not develop symptoms.