A new antibody test that shows if a person has been infected with coronavirus in the past has been approved by health officials in England.
Public Health England (PHE) said the test has an accuracy of 100 per cent, with the findings hailed as a “very positive development” in tackling the virus outbreak.
How does the test work?
The blood test has been developed by Swiss pharmaceutical company Roche and is designed to determine if a person has been exposed to the virus.
The test looks for antibodies which could help indicate whether a person has developed some immunity against the virus.
As it is able to detect 100 per cent of cases where a person has had coronavirus in the past, the test could prove useful in helping to inform when lockdown restrictions may be safe to ease.
Until now health officials have said such tests are not reliable enough, but after evaluation of the Roche test last week, PHE found it to be “highly specific”.
Professor John Newton, national coordinator of the UK Coronavirus Testing Programme, said: "We were confident that good quality antibody tests would become available when they were needed.
"Last week, scientific experts at PHE Porton Down carried out an independent evaluation of the new Roche Sars-CoV-2 serology assay in record time, concluding that it is a highly specific assay with specificity of 100%.
"This is a very positive development because such a highly specific antibody test is a very reliable marker of past infection.
"This in turn may indicate some immunity to future infection although the extent to which the presence of antibodies indicates immunity remains unclear."
When will the test be available?
Roche said it could supply hundreds of thousands of the tests each week, with the company first prioritising tests for distribution via the NHS, before looking at how they may be sold to individuals.
Health minister Edward Argard said the new test is intended to be rolled out to frontline NHS workers first, but did not specify a date for when testing will start.
The government plans to make the test available to workers in social care after the NHS and then distribute it more widely.
Will it be available in all parts of the UK?
The Department of Health and Social Care (DHSC) said it is exploring the use of antibody testing across the NHS in England, and later the wider public.
DHSC said it was delighted that devices were progressing through validation and is working on plans to roll out antibody testing, adding that an announcement will be made "in due course".
Health officials in Scotland, Wales and Northern Ireland make their own decisions about testing, but are likely to roll out the antibody test if England adopts it.
The test already has approval from medical regulators in the EU and the United States, although it is still not clear what amount of immunity from coronavirus a person might have if they have previously been infected.