An antibody test can detect if a person has had coronavirus before and has since recovered. The test, carried out by a device that pricks your finger for blood, works this out by testing your blood for coronavirus antibodies to see if they have already beaten the virus and gained some immunity to it. It can do this in about 15 minutes.

The coronavirus swab test that the Government currently uses can only tell whether a person has the virus, not if they have had it and recovered. These swab tests also take much longer to get a result.

The antibody test is also known as a "serological test".

The Government will look for a refund for millions of coronavirus tests ordered from China after scientists found they were too unreliable to be used by the public.

Ministers will attempt to recoup taxpayers' money spent on the fingerprick tests after an Oxford University trial found they returned inaccurate results.

The failure is a significant setback because it had been hoped the antibody tests would show who had already built up immunity, therefore offering a swifter route out of lockdown.

What is an antigen test?

An antigen test detects the presence (or absence) of an antigen, not antibodies. An antigen is a structure within a virus that triggers the immune system's response to fight off the infection. It can be detected in blood before antibodies are made.

An antigen test is effective because it can take a few days for the immune system to build enough antibodies to be detected in a test, however, antigens can be detected almost immediately after infection. So, in theory, the test can tell much sooner whether someone has the virus.

Antigen tests are used to diagnose HIV, malaria and flu.