Coronavirus antibody test: What is it and how can I get a home testing kit?

The test is not the same as an antigen test

The Royal College of Pathologists says boosting post mortems could help treat future Covid-19 patients (Getty/iStock)

In March, the NHS outlined plans to run 10,000 tests for coronavirus a day amid the pandemic.

Currently there are coronavirus antigen tests available to anyone with symptoms - although there have been widespread reports of these being inaccessible or people being offered tests hundreds of miles away from where they live.

But these tests are not the same as antibody tests, which show if you have had Covid-19 previously, not currently.

The NHS says: "Antibody tests are not widely available yet. Free NHS antibody test kits are currently only available for people living in England and Wales who work in adult social care.

“These tests are to help the NHS and scientists learn more about who has already had the virus and how it has spread in the UK.”

If you're unable to get an NHS antibody test, you can pay to have a test at a private clinic if you want to do so. But these are not officiated or credited by the health service or government. 

And on 21 September, at a Downing Street press conference, Professor Chris Witty said there were indications that antibodies “fade” in some cases after people have had Covid-19.

So what is an antibody test?

An antibody test, also called a serological test, is supposed to be able to detect whether a person has already had the coronavirus before, and has since recovered.

The test looks at individuals’ blood for coronavirus antibodies to see if they have already recovered from the virus and therefore may have gained a certain degree of immunity to it.

On 19 March, health secretary Matt Hancock tweeted that the government is “in negotiations for a brand-new type of antibody test — which can tell you if you’ve had the virus and are immune”, saying that the government planned on buying hundreds of thousands of tests.

During the daily press conference on Tuesday 24 March, the health secretary stated that the government had bought 3.5 million antibody tests “that will allow people to see whether they have had the virus and are immune to it and then can get back to work”.

However, on 6 April the government’s testing chief admitted that none of the 3.5 million antibody tests, which were ordered from China, were fit for widespread use.

On Thursday 14 May, it was reported that a “100 per cent accurate” antibody test had been approved for use in the UK for the first time.

The tests, which were developed by Swiss firm Roche, have already been in use in the US.

In late March, a Public Health England director said that 15-minute home test kits, which can determine whether a person has or has had the coronavirus, would be made available to the British public within days.

However, Professor Chris Whitty, the UK’s chief medical officer, later dismissed the claim the tests would be ready for circulation so soon, adding that frontline NHS workers would be prioritised for tests once they are available.

On Friday 17 April, the World Health Organisation (WHO) cast doubt on the use of antibody tests to detect immunity from Covid-19.

Expert epidemiologist Dr Maria Van Kerkhove informed a briefing that the presence of antibodies in the blood does not necessarily mean a person is no longer at risk of catching the virus again.

Where else are antibody tests being used?

In February, it was reported that Singapore had become one of the first countries to trial an antibody test.

The test, which was described as a “world first”, was developed by scientists at the Duke-NUS Medical School in Singapore.

On 23 March, Governor Andrew Cuomo of New York City stated that he would like antibody blood tests to be utilised so that healthcare workers who have immunity to the virus can return to work.

At a daily press conference, the governor said that a “serological drug” is being developed that would test the antibodies of individual to see “if they had the virus already”.

“We all believe thousands and thousands of people have had the virus and self-resolved. If you knew that, you would know who is now immune to the virus and who you can send back to work,” he stated.

During her briefing on Friday 17 April, Dr Maria van Kerkhove of WHO said: “There are a lot of countries that are suggesting using rapid diagnostic serological tests to be able to capture what they think will be a measure of immunity.

“Right now, we have no evidence that the use of a serological test can show that an individual has immunity or is protected from reinfection.”

On 29 April, it was reported that an antibody test to check whether someone has been infected with coronavirus, and said to be 99 per cent accurate, had been certified for use across Europe.

Global diagnostics specialists Abbott, which has a UK base in Maidenhead, said it was expecting to have shipped millions of the laboratory based lab tests across Europe by the end of May.

Can I get a home testing kit for antibodies?

An antibody test is a blood test to check if you've had coronavirus before. But this test is not widely available in England.

The government has instead focused largely on the antigen tests - those that show if you have Covid-19 currently.

An antibody test does not tell you: if you're immune to coronavirus, or if you can or cannot spread the virus to other people.

On 21 September, Chris Witty said there were indications that antibodies “fade” in some cases after people have had Covid-19.