Scientists have warned the public away from buying Superdrug’s coronavirus testing kits while doubts linger over their reliability and usefulness.
The accuracy of these antibody tests remains foggy, as does whether a positive result means a person is then immune to the disease.
The drugs store yesterday became the first to sell the tests which reveal if someone has had the infection, charging £69 for blood sample analysis.
Widespread antibody testing has long been heralded as the breakthrough needed to end blanket lockdown as it could potentially flag up who is immune to Covid-19.
Superdrug has insisted the test, manufactured by US-based pharmaceuticals firm Abbott, is accurate, but experts urged consumers to take this with a dollop of caution.
Abbot itself has said the tests were not meant to be used DIY, but blood samples are instead supposed to be taken by a trained health worker.
Professor Stephen Powis, NHS medical director, told people to hold off purchasing the tests until government scientists drill down deeper into its accuracy.
Superdrug has become the first high street retailer to sell a coronavirus antibody test to the public for £69 with almost 100 per cent accuracy
A notice on Superdrug’s website this afternoon said ‘Due to the high demand of orders, this service is currently not available’
WHY IS ANTIBODY TESTING IMPORTANT?
WHAT IS AN ANTIBODY TEST?
Unlike tests to diagnose diseases, antibody tests show who has been infected and recovered.
The body makes antibodies in response to many illnesses and infections, including other coronaviruses. New blood tests are being developed to identify antibodies unique to SARS-CoV-2, the official name of the new coronavirus.
The tests look for two kinds of antibodies: immunoglobulin M (IgM) and G (IgG). The body quickly produces IgM antibodies for its initial attack against infections. It makes IgG antibodies more slowly and retains them longer; IgG antibodies suggest possible immunity.
WHAT IS THE DIFFERENCE BETWEEN RAPID TESTS AND ASSAYS?
Some companies are developing finger-prick tests that get results in minutes. These are called immunoassays and will form the basis of home testing kits.
Others are developing far more accurate tests called enzyme-linked immunosorbent assays (ELISA) that require sending blood samples to a lab for analysis.
HOW CAN ANTIBODY TESTS HELP END LOCKDOWNS?
Antibody tests can help calculate what portion of the population has already been infected, as well as whether infections were mild or severe.
Governments and companies could use antibody tests to determine who would most likely be safe to return to work and public interactions, and whether it is safe to lift stay-at-home orders all at once in some regions or in stages based on infection risk.
People with negative antibody tests or very low antibody levels would likely have higher risk of infection than people with high antibody levels.
DO ANTIBODIES TO THE NEW CORONAVIRUS CONFER IMMUNITY?
While antibodies to many infectious diseases typically confer some level of immunity, whether that is the case with this unique coronavirus is not yet known.
And how strong immunity might be, or how long it might last in people previously infected, is not clear. With some diseases like measles the immunity can be lifelong. With others, immunity can wane over time.
Scientists cannot know with certainty that reinfection is not possible until further research.
Antibody tests could inform not just lockdown exits, but the best approach to treatments and vaccines.
Speaking at the Downing Street press briefing, he said: ‘I would caution against using any tests that might be made available without knowing quite how good those tests are.
‘Public Health England as I say is evaluating them for the NHS so I would caution people against being tempted to have those tests.’
He added: ‘What we don’t absolutely know at the moment is whether having antibodies, and having the antibodies that are tested in those tests, means that you won’t get the virus again.
‘I wouldn’t want people to think just because you test positive for the antibody that it necessarily means that you can do something different in terms of social distancing or the way you behave.
‘Because until we are absolutely sure about the relationship between the positive antibody tests and immunity, I think we as scientists would say we need to tread cautiously.’
Scientists around the globe are urgently trying to establish whether, like many viruses, your body develops immunity once you contract the infection.
When a virus attacks your body, antibodies are produced to fight the disease and so their presence signals if you have it the virus.
Adam Finn, a professor of paediatrics, University of Bristol, who is in the field of developing an antibody test for Covid-19, said until the science is clear there is no point spending money on an antibody test.
‘Until we know how strong and long lasting immunity is after infection, it is hard to know what to do about the results of these tests, even if the tests are reliable,’ he said.
‘So the bottom line is: don’t spend money and time on any test unless you have a very clear idea of what the result does or does not mean for you and what you are going to do or not do if you get a positive or negative result.
‘If the answer is that the result is not going to change what you do because you can’t be sure what it means, then there’s no point in doing the test.’
He was echoed by Professor Gino Martini, chief scientific officer at the Royal Pharmaceutical Society, who added: ‘Any antibody test at present can only provide a partial picture.
‘The real issue is that no-one knows the level of immunity that is conferred by having antibodies to coronavirus, how long it might last, and if you can become re-infected. We need much more information and data on immunity before we can understand the importance of having antibodies to the virus.’
Yvonne Fovargue MP, who chairs a parliamentary panel on consumer protection, told the Telegraph that ‘Superdrug seems to be playing on people’s fears and that’s not right. What people really need is a readily available, easy to use test that’s accurate’.
The test is produced by medical giant Abbott and has been given the seal of approval by Public Health England
WHAT ANTIBODY TESTS ARE APPROVED SO FAR?
Antibody tests made by Abbott and Roche are the first antibody tests to be ratified as accurate by Public Health England, after weeks of disappointments.
The tests detect whether someone has had the virus and then recovered which could indicate they may be immune.
PHE said the ratification of the two tests performed in its labs was a ‘very positive development’.
Both are likely to be used in the ‘test, track and trace’ programme being launched next week, in which anyone who has been in contact with a coronavirus patient will be tested.
The Department of Health is in conversations with both firms about incorporating the kits into its testing programme, with NHS staff likely to be first to get access.
The Abbott test is also being sold privately for home use by health tech firm Babylon and retailer Superdrug for £69.
Home use of the test which uses a spot of blood from a finger prick rather than a full blood sample has only been confirmed as accurate by an independent lab, and not yet by PHE.
Scientists have stressed that although the two tests offer useful information about who has been infected, it is not yet clear what proportion of these people will be immune to the disease.
The idea of ‘immunity certificates’ has been shelved for now because of this, although No 10 said it was still exploring it.
Hopes have run high since March that antibody tests could allow employees to return to work.
Health Secretary Matt Hancock ordered 3.5million tests but it turned out the best of them could spot only 70 per cent of those who had been infected.
The new tests resolve that problem by using proven lab-based technology, rather than the ‘pregnancy-test’ style kits Mr Hancock had pinned his hopes on. They also generate very few ‘false positives’ which means indicating someone has been infected when they have not.
The tests, which are intended to tell someone if they have had the virus in the past, cost £69 and require the user to take blood samples themselves and post them off to a laboratory, where it takes 24 hours to produce a result.
In a notice on the shop’s website this afternoon it said: ‘Due to the high demand of orders, this service is currently not available’.
And the medical giant Abbott, which makes the tests, has insisted that its tests were not intended to be used by people taking their own blood samples.
Instead, the Illinois-based firm says its tests have only been evaluated to be accurate on blood samples taken by trained healthcare providers directly from patients’ veins.
Any test that has a CE mark such as the one made by Abbott can be legally sold and used in the UK but health chiefs have repeatedly urged Britons to avoid tests that haven’t been approved.
Officials last week approved the Abbott test for laboratory use, making it only the second kit of its kind to be given the green-light following a similar kit made by Swiss giant Roche.
No home ‘pregnancy-test’ kits have yet been approved, despite promises in March that one would be available.
Known as the ‘have you had it’ tests, antibody tests reveal whether someone has been infected with COVID-19 in the past and recovered from it, but scientists are still unsure whether this means they are protected from catching the virus again.
Therefore, some say there is ‘no point’ paying for a test because it is still not clear what the results mean.
Superdrug urges individuals to continue social distancing and following government guidance even if their result is positive.
Superdrug started selling the kit this morning on its Online Doctor service for £69, but said it isn’t available in store.
It requires a few drops of blood collected by a finger prick taken at home which are sent off in a pre-paid envelope to The Doctors Laboratory. Blood is then placed into a vial, which must be filled until a certain level.
Michael Henry, Superdrug’s healthcare director, said he is ‘confident’ the test is accurate and reliable.
It was the second antibody test to be approved by the government’s testing chiefs and is soon expected to be used by professionals in the NHS and in public surveys.
The first was that manufactured by Swiss firm Roche, called Elecsys, which is also not designed to give people a result in the comfort of their own home.
Both tests have been described as ‘game changing’ by PHE which conducted an analysis of it.
Ministers are in talks with Roche to buy millions of the tests, which will be given to NHS and social care workers for free. It is not clear if they will ever be given to the public.
Abbott’s antibody kits are on standby for NHS use and a spokesperson said last week the firm had capacity to provide five million tests a month to the UK ‘with immediate effect’.
But anyone over the age of 18 can now privately buy the Abbott test on Superdrug, so long as they do not currently have symptoms of the virus because it takes at least 14 days for antibodies to be made.
Babylon is selling it for the same price, while another Northampton-based company checkmybodyhealth.co.uk is offering the Abbott test for £89. London-based privatecoronavirustests.com is selling it for £99.
The test is 97.5 per cent sensitive, which means just over 97 people in 100 who test positive have indeed been infected.
The other three people, however, would get an inaccurate result – known as a false negative result. They will be told they do not have antibodies when in fact they do.
The test has 100 per cent specificity, which means it will never generate a ‘false positive’ result – when people are incorrectly led to believe they have antibodies.
Experts say is it better to compromise on sensitivity than specificity, because ‘false negatives’ can have dangerous consequences.
However, commenting on the test, Stephen Evans, a professor of pharmacoepidemiology, London School of Hygiene & Tropical Medicine, said: ‘This seems rather a strong claim since to be absolutely sure (‘never’), an infinite number of people will have to have been tested.’
Will Irving, a professor of Virology, University of Nottingham, said although it is reassuring claims test to be very accurate, it depends entirely on how the company came to that conclusion.
He said: ‘The sensitivity data will be dependent on what kind of serum samples have been tested. If these are mostly or all from hospitalised patients, then the figure may be an overestimate, as there are data suggesting that individuals who don’t become very ill with COVID-19 may not make very high levels of antibody.
‘The same is true of specificity.’
Ministers are in talks with Roche to buy millions of the tests, which will be given to NHS and social care workers for free. The Roche test, called Elecsys (pictured), is also not designed to give people a result in the comfort of their own home.
Medical giant Abbott has produced a test which is essentially the same as the antibody test announced by the Government last week, manufactured by Swiss firm Roche.
Scientists welcomed the development in antibody testing. But rallied to remind the public that various antibody tests being sold privately online are a gamble, even if approved by officials.
Babylon’s Dr Olivia Morrow who is helping to lead the company’s coronavirus testing effort says an antibody test ‘can help give answers to people who are unsettled, wondering if that cough, fever, or loss of smell they had in February was COVID-19’.
Users can also choose to opt-in to share information to aid national research by institutions such as PHE, according to the company. It’s not clear if this is the case for Superdrug.
PHE is conducting a surveillance programme to understand how many of the population have had the virus using their own, high accuracy antibody test operated at their Porton Down science campus.
Millions of Abbott’s lab-based tests have been shipped to customers across the US after it was granted an Emergency Use Authorization (EUA) from the FDA.
Abbott plans to ramp up to 20million antibody tests in June and beyond.
It’s hoped that one day, CE-marked home testing kits, also called lateral flow tests, will become available.
But they have to be proven to work, first. Health chiefs are still on the hunt for an accurate immunoassay test since ministers promised one back in March.
The finger-prick test generates results in minutes at home. The results are displayed like a pregnancy stick and don’t need the help of a laboratory of doctor.
Such a test was touted as the key to lifting lockdowns because it would mean people could buy a test quickly online, find out if they have had the virus and return to work or not.
But progress has been halted because scientists have warned it’s still to early for them to know what the antibodies show, exactly.
There are hundreds of companies designing these tests, but so far, none tested by an Oxford University team have passed stringent protocol.
PHE has not disclosed how many samples its evaluations were based on before giving Abbott (or Roche) the green light.
Superdrug doctor ambassador, Dr Zoe Williams, made clear the new test does not confirm someone is safe to go back to work or mingle in society.
She said: ‘There are however things to consider before taking it.
‘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.’
Scientists have warned the public away from buying Superdrug’s coronavirus testing kits while doubts linger over their reliability and usefulness.