The Wild West of Covid-19 antibody tests needs a sheriff

As with many other things, the Covid-19 pandemic has delayed the blockbuster fraud trial of Elizabeth Holmes.

Her start-up Theranos went from darling to dumpster fire in a matter of months after The Wall Street Journal exposed huge flaws in the company's promise that its blood-test kits could detect an array of illnesses from a single "finger-prick" of blood. (Holmes has denied the charges.)

Ironically, the pandemic may be recreating a similar environment to the one that cultivated Theranos in the first place, as whistle-blower Tyler Shultz, a former employee at the now-defunct start-up, warned on May 2.

Pointing to a combination of large-scale health needs, the potential for lucrative financial gain and corner-cutting by regulators, he concluded that Theranos would be "thriving" in this pandemic.

And when it comes to Covid-19 antibody tests, he has a point. A deluge of new rapid test kits has offered a seductive vision: A single finger-prick of blood is all it might take to see if you've been infected with the coronavirus in the past and generated antibodies that protect against future reinfection (though this is a topic of debate).

This is a potentially huge market. Governments have spent millions on test kits, part of efforts to track the spread of Covid-19 as they start to ease draconian lockdowns. And individuals are desperate to know whether they've already had the disease. If a consensus emerges that antibodies do confer a degree of immunity, it could be the golden ticket to freedom from social distancing and home isolation.

Companies are even selling tests direct to the consumer, not just to healthcare professionals. The problem is that many of these antibody tests simply aren't good enough.

In Britain, a study of nine unidentified commercially available tests found them all to be "unsuitable for testing individuals". The devices scored especially poorly on their ability to avoid false negatives, called sensitivity, with a range of 55 per cent to 70 per cent accuracy. Specificity, or the ability to avoid false positives, fared better at 95 per cent to 100 per cent. After ordering millions of test kits from China, the British government is trying to get its money back.

The rush to market in a pandemic is bad enough, but regulators have also been slow to wake up to the real risk of fraud.

The United States Food and Drug Administration in March allowed the sale of unauthorised antibody tests under certain conditions, only to tighten the rules last week. "We unfortunately see unscrupulous actors marketing fraudulent test kits and using the pandemic as an opportunity to take advantage of Americans' anxiety," it said.

And while several European countries have issued consumer warnings, it's still possible to take tests that haven't undergone regulatory authorisation in countries such as France. Only Belgium has banned rapid testing kits.

Obviously, it would be wrong to imagine that every actor in this market is unscrupulous and that potential Theranoses are everywhere. And accuracy isn't an impossible dream. Laboratory sample tests known as Elisas (for enzyme-linked immunosorbent assays) have been shown to have high specificity and high sensitivity, though they must be administered by trained medical staff and can't be used at home.

Roche, meanwhile, is preparing to roll out a lab test in Britain with what it says is a specificity above 99.8 per cent and sensitivity of 100 per cent (when conducted 14 days after a confirmed infection).

But, in general, too much burden is being placed on the consumer to trust and make sense of technical information. A test promoting a figure of 95 per cent accuracy may sound reliable, but in a population of one million people where 15 per cent have been infected, it actually works out to 42,500 false positives and 7,500 false negatives, according to the Johns Hopkins Bloomberg School of Public Health.

Errors might keep people cooped up at home and unable to work, or start a new epidemic chain. This is a "Wild West" market that's crying out for sheriffs.

Cracking down on poor-quality tests is an obvious first step. The next should be to ramp up independent oversight of all tests coming to market, ideally worldwide.

Rather than rely on manufacturers' own data, or have national regulators separately test different kits, organisations like the European Centre for Disease Prevention and Control or the World Health Organisation look well placed to pool resources and save time while setting much-needed standards, Iceland's chief epidemiologist Thorolfur Gudnason tells me.

Theranos sold a product that was too good to be true. We don't yet know if Covid-19 will produce a similar scandal, but this is a market that's overdue a cleanup. When a whistle-blower reaches for his whistle a second time, it's worth paying attention.


Lionel Laurent is a Bloomberg Opinion columnist covering Brussels. He previously worked at Reuters and Forbes.

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A version of this article appeared in the print edition of The Straits Times on May 12, 2020, with the headline The Wild West of Covid-19 antibody tests needs a sheriff. Subscribe