Update for 27 May 2020: Laboratories supplying COVID-19 antibody test kits to the public have been asked by the medicines regulator to pause the sale and analysis of these tests while a review of the process is undertaken.
Anyone who has bought an antibody test (where you take a finger-prick blood sample at home and send it off to a lab) will have to wait until the review is concluded before they can get their results.
New tests of this type should not be available to buy at this time, and results from previous tests should not be assumed to be accurate.
As coronavirus testing becomes more widespread in the UK, find out what you need to know about the different types of test, how to get one, and why not to spend money on pricey private tests.
Anyone in the UK displaying symptoms can now apply for an antigen test – to tell you whether you currently have COVID-19.
Meanwhile, antibody tests – which tell you if you’ve previously had COVID-19 – were recently on sale to the general public, but the Medicines and Healthcare products Regulatory Agency (MHRA) has requested a pause on these pending verification of the sampling process.
It’s important to know the difference between the two tests, what’s available and what’s legitimate, as well as the limitations of antibody testing.
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COVID-19 testing explained
There are two broad types of test available and it’s important to understand the differences:
This swab test, usually take from inside the nose or mouth, already exists and indicates whether a person is currently infected with the disease. This type of test takes longer to process as the samples need to be analysed in a lab.
Antigen testing now available to anyone with symptoms
The government has now expanded eligibility for coronavirus antigen testing to anyone displaying symptoms.
You can request this swab test online, and it can be done either through a drive-through testing centre or via a home test kit. It tells you whether you’re currently infected with COVID-19. It involves swabbing the inside of your nose and the back of your throat, using a long cotton bud.
The government website warns that demand for testing is high and it cannot guarantee people who ask for a test will actually get one – it depends on daily availability in different parts of the country.
Testing must be done within the first five days of having symptoms. The NHS advises requesting a test within the first three days. You can book a test online through the NHS.
This service covers both drive-through centres and home test kits for people in England, Scotland and Northern Ireland, and covers home test kits for people in Wales.
Drive-through tests or mobile testing units are not currently available to members of the public in Wales, as these are still being reserved for symptomatic critical care workers.
Note that the government has warned that there is ‘very high demand’ for tests, and whether you’re able to get a test or not will depend on the daily availability in different parts of the UK.
People in hospital and essential workers, including NHS and social care staff, are still getting priority. Testing is also available for asymptomatic care home residents and social workers, as well as NHS staff and patients.
Some private companies have also been offering this type of test, but have come in for criticism due to very high prices.
This blood test should show whether a person has already been infected by detecting the presence of the antibodies our bodies produce to kill the virus.
Health officials in England have approved an antibody test, manufactured by Swiss company Roche. The test has previously been approved by the FDA in the US and by some European health regulators.
It is not yet available to the general public in the UK, but is beginning to be rolled out to health and social care staff, patients and care home residents. Health Secretary Matt Hancock said that each devolved nation is deciding how to use its test allocation and how testing will be prioritized and managed locally.
The antibody test needs to be analysed at a laboratory or hospital with the appropriate equipment. It has been shown to be highly accurate, and is therefore the first approved antibody test that can reliably identify if somebody has had COVID-19.
This is an important step as it increases potential for wider testing and identifying the spread of the disease. Expanding accurate antibody testing would help experts understand how far the virus has spread, and how many people might have had it asymptomatically, or with mild symptoms.
Antibody tests are measured on specificity – which measures the proportion of ‘true’ negatives – and sensitivity, which measures the proportion of ‘true’ positives. The Roche test, analysed using a machine already widely available in hospitals and labs, is said to have greater than 99.8% specificity and 100% sensitivity.
This is important because it means that people won’t get a false positive result and think they’ve got the antibodies when they don’t, or vice versa.
It does specify that blood samples should be taken at least 14 days after a person suspects they developed the disease, though.
Antibody test kit sales paused
With the wave of publicity surrounding the news, an increasing number of private companies are marketing this type of test to the general public, including from Superdrug’s Online Doctor service and virtual healthcare giant Babylon Health.
But companies supplying these tests have been asked by the MHRA to stop selling them for now, and not provide customers with results until a review of the process has been undertaken.
These tests require you to take a blood sample by pricking your fingertip, and sending it off in a vial to be analysed by a lab. What the MHRA is looking into is the process of taking a blood sample from your fingertip at home, and whether samples collected in this way will yield accurate results.
Not all antibody tests are equal
The officially approved antibody test is not yet available to the public. The process is different from the commercial tests as it uses a blood sample taken from a vein, and must be administered by a healthcare professional in a clinical setting.
No home test kits for COVID-19 where you conduct the test and instantly get a result at home can legally be sold int the UK, so you should be cautious of any company claiming to sell them. Validation tests on this type of home test kit revealed that they weren’t very accurate, so the ones bought by the government were abandoned.
The Medicines and Healthcare products Regulatory Agency (MHRA) has raised concerns that the confusion around the availability of testing kits could also fuel the marketing of fraudulent test kits by scammers.
Still plenty of unknowns around COVID-19 immunity
It is hoped that once someone has had COVID-19, they are immune to the disease, but crucially, this is still uncertain.
The WHO says that ‘we expect that most people who are infected with COVID-19 will develop an antibody response that will provide some level of protection. What we don’t know yet is the level of protection or how long it will last’
It warned against making assumptions about a person’s immunity to COVID-19 based on antibody testing. A positive result shouldn’t yet be interpreted as a stamp of immunity.
Buying an antibody test: what you need to know
Sampling antibody tests which are analysed at a lab, similar to the Roche test, have up until today been available to the public. For now, the sale of these tests has been paused, so you won’t be able to buy one.
The MHRA has asked laboratories to pause analysis of self-collect finger-prick samples for coronavirus antibody testing, while they undertake a review of the end-to-end process.
Customers who have already bought a test will have to wait for the MHRA review to be concluded until they can access their results. If you have already bought a test and received your results, the MHRA says not to rely on their accuracy.
We’ve previously advised caution about spending money on an at-home COVID-19 antibody test, as there could be a risk that they encourage a false sense of security with a positive result. NHS England’s Medical Director Stephen Powis cautioned the public against purchasing these tests, which preceded the action that has now been taken by the MHRA.
Superdrug recently became the first high street retailer to offer a COVID-19 antibody test (above). Its test cost £69 and had been available via Superdrug’s Online Doctor service – not in stores.
Superdrug’s doctor ambassador, Zoe Williams commented that the test would be supplied with counselling and medical support, but noted that ‘receiving a positive antibody test result does not confer immunity, and it is important that people understand a positive test result does not mean you can be any more relaxed with the required hygiene and social distancing measures as set out by the government.’
Antibody tests have also been available from private healthcare firms including home blood-testing companies Forth, Blue Horizon Medical, and online GP companies Babylon and Qured, costing £69 – £99.
Each company states in the small print that there is not enough evidence proving the link between the type of antibodies the tests detect and whether these confer immunity to COVID-19.
Sarah Bolt, CEO of Forth, told us the test would help remove a level of uncertainty as to whether you’d had the virus or not.
She said: ‘at this stage, it is not yet known the depth and length of immunity these antibodies provide, as the virus is relatively new. We hope that it is similar to other viral infections in providing lasting protection.’
Qured told us, ‘the Qured test is being purchased by individuals and employers who want to understand whether they or their workforce have been exposed to the virus and had a detectable immune response.’
Any company selling an at-home test, where you take a test at home and get a rapid result that you read yourself, should be avoided. No test of this type is approved by the MHRA and selling them in the UK is illegal.
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For now, the best thing you can do is follow the social distancing guidelines and guidance on how to protect yourself and others.