The buzzy idea is impractical, critics said. And there isn’t yet real-world data to show it will work.
By Katherine J. Wu
Over the past few weeks, a Harvard scientist has made headlines for a bold idea to curb the spread of the coronavirus: rolling out so-called antigen tests, a decades-old underdog in testing technology, to tens of millions of Americans for near-daily, at-home use.
These tests aren’t very good at picking up low-level infections. But they’re cheap, convenient and fast, returning results in minutes. Real-time information, argued Dr. Michael Mina, would be a lot better than the long delays clogging the testing pipeline.
The fast-and-frequent approach to testing has captured the attention of scientists and journalists around the world, as well as top officials at the Department of Health and Human Services.
Deployed often enough and widely enough, speedy tests could “really squash the virus,” Dr. Mina said. “I think it’s crazy not to get behind this.”
But more than a dozen experts said that near-ubiquitous antigen testing, while intriguing in theory, might not fly in practice — and is unlikely to be a pandemic panacea. In addition to posing herculean logistical hurdles, they said, the plan hinges on broad buy-in and compliance from a country full of people who have grown increasingly disillusioned with testing for the virus. And that’s assuming that rapid tests can achieve their intended purpose at all.
“We are open to thinking outside the box and coming up with new ways to handle this pandemic,” said Esther Babady, director of the clinical microbiology service at Memorial Sloan Kettering Cancer Center in New York. But antigen tests that could work at home have yet to enter the market, she said.
And no one has yet done a rigorous study to show that fast-and-frequent trumps sensitive-but-slow in the real world, she said: “The data for that is what’s missing.”
Although fast-and-frequent testing could work, what’s been put forth so far about the approach has been “largely aspirational, and we need to check it against reality,” said Dr. Alexander McAdam, director of the infectious diseases diagnostic laboratory at Boston Children’s Hospital, who recently co-authored an article on pandemic testing strategies in the Journal of Clinical Microbiology.
Most of the coronavirus tests run so far rely on a laboratory technique called PCR, long considered the gold standard of infectious disease diagnostics because it can pick up even very small amounts of genetic material from germs like the coronavirus.
But sputtering supply chains have compromised efforts to collect, ship and process samples for PCR, driving delays in turnaround times. The longer the wait, the less useful the result. PCR also isn’t cheap or user-friendly, making it an unlikely candidate for widespread home use.
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