LONDON — It was promoted as a potential coronavirus game changer, a breakthrough that would allow millions of people to resume their daily lives within a matter of days.
Governments and companies across the world put great faith in the idea of an “antibodies test” — a home-administered finger-prick kit, designed to detect whether someone has had the coronavirus in the past and, crucially, built up immunity.
But the initial optimism was dented this week after leading British scientists revealed that none of the tests they had tried so far were accurate enough to be of any use. The U.K. government, whose prime minister, Boris Johnson, is in intensive care with COVID-19 symptoms, said it had ordered millions of the kits and was now seeking refunds.
“Sadly, the tests we have looked at to date have not performed well,” Sir John Bell, the Oxford University professor heading up the tests for the British government, wrote in a blog post Sunday. “We see many false negatives … and we also see false positives.”
The U.K. “is now uniquely positioned to evaluate and find the optimal test for this disease,” but no country in the world has found a kit that is up to standard, he said.
Finding one “should be achievable” but will take at least a month, he added.
His views were echoed by the U.S.’s top infectious diseases expert, Dr. Anthony Fauci., who told the JAMA health journal on Wednesday: “You have to validate the tests otherwise go down a path that would be very misleading.”
The British findings came days after the Spanish government said it had sent back another shipment of inaccurate antibody tests, bought from a European firm that had sourced them in China.
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Different from the nasal and throat swabs that tell you whether you currently have COVID-19, the disease caused by the coronavirus, the antibody test — also called the serology test — looks a bit like a pregnancy test, with results on a series of lines on a strip. It takes just 20 minutes to complete, and can be done at home or at a pharmacy.
In theory, they could tell whether someone has already had the virus, even if they had not shown any symptoms. This could allow people to resume daily life with the confidence that they had built up some immunity.
Governments in London and Berlin have already floated the idea that these people could get “immunity certificates” to show that they pose no threat to themselves or others.
This led to fears that some people might seek infection so they could recover and return to work, but for those who had genuinely survived the virus, it held the promise of a degree of freedom.
Some officials cast this as the first step to an exit strategy, while offering bold predictions on when the tests might be available.
“That will happen this week,” Sharon Peacock, director of the U.K’s National Infection Service, said March 25, suggesting the tests would be available on Amazon and at local pharmacies. “In the near future people will be able to order tests that they can conduct themselves.”
As the widespread societal lockdowns covering much of the world continue in a bid to buy time until a vaccine can be found, testing is seen as crucial to tracking and tackling the disease.
In the U.S, the Federal Drug Administration is issuing its first Emergency Use Authorization for these tests.
One firm, Scanwell Health, a digital health care company based in Los Angeles, is seeking government clearance for a kit that lets users submit a scanned image of a blood test to doctors via their phones.
While theoretically simple for people to administer, the tests are quite complex. They would require that blood that a test-taker donated before the epidemic be available to detect false positives that might come from the antibodies of other types of coronavirus.
The mantra among experts is that the only thing worse than no test is a bad test, so mistakenly telling thousands of people they are immune could be catastrophic.
According to the United Kingdom’s Department of Health, there are around 100 kits on the market but no government in the world has developed an antibody testing program that is up to the necessary standard — comments echoed by Franco Locatelli, the head of Italy’s Higher Health Council.
Spain sent back an unspecified number of antibody tests it had bought from a European intermediary that used a Chinese supplier, and Maria Jose Sierra, a doctor who is deputy of the country’s Emergency Coordination Center, said Monday that the test’s accuracy was as low as 64 percent.
In Germany, the health ministry warned anyone thinking of buying rapid antibodies tests online that the kits were most likely to be inaccurate.
There is a significant risk, it said, that “the person being tested is already highly infectious and imagines themselves to be safe.”
