A rapid Covid-19 test launched by the founders of fashion retailer Boohoo has attracted criticism over its accuracy and usefulness.
With Europe buffeted by a new surge in coronavirus cases and governments struggling to process enough tests, a flurry of private tests is being rushed to market. Their speed of development and lack of uniform validation has led to serious concern among experts.
Medusa 19, a biotech company created in March this year by Boohoo founders Richard Hughes and Mahmud Kamani, has started selling a test that works by users spitting into a tube and gives results in 10 minutes.
Mr Kamani, the 55-year-old chairman of Boohoo, who was enmeshed in a scandal over allegations of poor working conditions in its supply chain this year, owns a 15 per cent stake. Mr Hughes, who described himself to the FT as the “brawn” of the company, holds a 75 per cent stake.
The company says its “saliva protein test” - which is sold to corporate customers for £29.99 each and needs to be administered by a doctor or nurse - can tell individuals both whether they have had Covid-19 in the past and whether they have the virus now.
But testing experts have raised concerns that these claims are “misleading”, given that it is an antibody test and antibodies only tend to develop several days after infection. For this reason, the World Health Organisation does not recommend the use of antibody-detecting rapid diagnostic tests to find cases of current infection.
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According to preliminary clinical trials, the test has 92 per cent specificity, meaning nearly a tenth of users would get an incorrect result.
The MHRA, the UK medical regulator, has set a target of 99 per cent specificity for rapid antigen tests and 98 per cent for rapid antibody tests.
“The specificity of this test is appalling compared to RT-PCR [the common antigen tests] and other antibody tests,” said Jon Deeks, professor of biostatistics at Birmingham university and lead author of a continuing review into antibody testing by Cochrane, the independent global health organisation.
He noted that the false positive rate was found to be 1 to 2 per cent for conventional blood-based antibody tests, “so using this test will create 4 to 8 times as many false positives as other tests”. He added: “This is really bad.”
But Christian Stephenson, chief development officer at Medusa 19, said the tests were to be taken as “triage tests”.
“It will indicate a current infection, but if you test positive you should still have a confirmatory PCR test,” he said. “If we could screen people before, to reduce the bottleneck in the government, we could stop the roadblocks on testing at the moment.”
The antibody test has received a European “CE mark” for quality assurance.
“All the CE marking does is tell you it’s barely adequate,” said Richard Tedder, visiting professor in medical virology at Imperial College London, who invented the HIV antibody test in the 1980s. “One in 10 people will get a false result and that is not acceptable for clinical use.”
Medusa 19, which is registered as operating out of a property in Manchester owned by the Kamani family, said it has manufactured 2.5m tests in the past two weeks at its factory on the Wirral and would increase production to 100m within six weeks. Mr Stephenson said it had received “a lot of interest from international governments”.
“We believe there’s a good opportunity that the Spanish are going to take it for all students in Spain,” said Mr Hughes. “We’ve used expertise from Crawford [a previous biotech venture] and Boohoo to scale this — we know how to scale.”
The company claims that its test — the only saliva-based antibody test on the market in the world — is able to detect Covid-19 antibodies much earlier than other tests that use blood samples and are “not sensitive enough due to a high dilution effect”.
Referring to Medusa 19’s claim about heightened sensitivity, Mr Deeks said that the numbers of presymptomatic and asymptomatic people tested is not made clear in the company’s literature and must be based on very small samples, “so they probably are getting a little over excited about what the data are showing them”.
Mr Tedder said: “To say it can tell you if you currently have Covid-19 is a distortion of the truth. There’s so many of these tests that we’ve got to chuck out; it’s really dangerous.”
Mr Hughes responded that “it’s too easy for people to be ignorant of the facts”. “It’s brutally obvious that this test has a role to play in the fight against Covid,” he said. “The saliva antibody test we’ve got and the detection rate is highly encouraging. Ours is available in mass scale at the moment, no one else’s is so this has to be a good thing.”
Initially, the plan was to bring an antigen test to market and a distribution agreement was made with Aim-listed biotech company Avacta for the sale of the rapid antigen test Avacta is currently developing.
While the Avacta test awaits regulatory approval in the UK, Medusa 19 launched its own test. Avacta issued a statement in August clarifying that results from Medusa 19 did not relate to their test in development.
The Royal Statistical Society announced on Thursday that it had launched a new working group to advise on the development of statistical evidence around diagnostics tests, which it said was “created in response to concerns about a lack of basic statistical evidence on clinical and analytical performance of a number of new diagnostic tests that are available”.
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