Britain has given the green light to a Swiss coronavirus antibody test that will be rolled out to millions in the coming months.
Public Health England (PHE) found the tests were 100 per cent reliable in an independent evaluation.
Drugmaker Roche Holding AG says it is now in talks with the UK government to offer the antibody test kits across the country.
"This is a very positive development because such a highly specific antibody test is a very reliable marker of past infection," UK's coronavirus testing programme coordinator John Newton said.
"This in turn may indicate some immunity to future infection although the extent to which the presence of anti-bodies indicates immunity remains unclear."
The findings from the government's public health agency come as England began easing its coronavirus lockdown, with people in manufacturing and certain other sectors being asked to return to work if they can not work from home.
Prime Minister Boris Johnson has previously described antibody tests as a "game-changer", as they show who has already had the virus and may have a degree of immunity, meaning those people can potentially resume social contact with others and return to work.
Roche said in a statement late Wednesday it is now in talks with the UK's National Health Service (NHS) and government about a phased roll-out of antibody test kits as soon as possible.
Roche expects production to reach the high double-digit millions by June and pass the 100 million monthly threshold later this year.
“We are working closely with the NHS, public health bodies and the UK government to enable the roll out of our test across the UK as soon as possible,” it said in a statement.
“We will be able to provide hundreds of thousands of antibody tests to the UK per week.
Health Secretary Matt Hancock had earlier said the government was in discussions with the Swiss drugmaker over antibody testing.
It comes after Britain has suffered a number of mishaps with antibody tests in recent months, buying faulty kits that were not effective.
Earlier this month, Roche's antibody test won emergency approval from the US Food and Drug Administration.
Unlike tests to diagnose diseases, antibody tests show who has been infected and recovered.
It could pave the way for many more people to return to work if they know they have had the virus.
As part of its virus response, the UK has been increasing its coronavirus testing capacity in recent weeks to more than 100,000 per day, but these are antigen tests, which only show whether someone currently has the virus.
“We are delighted that devices are progressing through validation, and are actively working on our plans for rolling out antibody testing and will make announcements in due course,” a Department of Health and Social Care spokesperson said.
“Antibody testing is an important part of our strategy to counter the spread of Covid-19 and to help us understand who has had the disease.”
The UK has recorded 33,186 deaths from Covid-19 to date and is now the country worst-hit by the respiratory disease in Europe.
