Updated on November 20, 2020.
Coronavirus infections in the United States are growing exponentially, and lawmakers may soon face an awful choice between another round of shutdowns and the deaths of tens of thousands more Americans.
A small band of scientists insist there is another way. They say that if every American took multiple coronavirus tests a week at home, we’d be able to figure out who is contagious. People who tested positive would stay home for two weeks while the rest of us more or less went about our lives. With masks and social distancing, yes—but also with safer schools and larger funerals.
These rapid tests, these scientists argue, would help Americans survive until a vaccine becomes widely available next summer. A similar testing scheme conducted in Slovakia recently helped cut infections in half, Reuters reported. Other studies have suggested that testing people for symptoms, such as fevers, alone won’t stop the spread of the coronavirus, and that everyone—symptomatic or not—should be tested frequently.
But the easy, cheap, at-home coronavirus tests that would make all of this possible still aren’t available to most Americans.
My colleagues Robinson Meyer and Alexis C. Madrigal wrote about the promise of such testing in August. At the time, the concept had circulated for months. A handful of at-home tests are now for sale in some stores, but they cost more than $100 and take more than a day to return the results. Yesterday, the FDA approved another at-home test, Lucira, that will cost less than $50 and return results within 30 minutes. But it will be available only by prescription, NPR reported, and won’t be widely available until this spring. The types of tests scientists such as the Harvard epidemiologist Michael Mina, an advocate for the idea, are envisioning are extremely cheap—a few bucks a pop—and wouldn’t require a prescription.
Mina and others suspect that at-home COVID-19 testing isn’t widely available yet because President Donald Trump and his administration haven’t tried particularly hard to make it so. “The only reason that we don’t have these out in massive numbers is that the federal government hasn’t prioritized it in any way,” Mina told me recently.
Though the Lucira news is encouraging, Mina sees it as a “baby step.” He said the feds should be pumping money into the companies developing and manufacturing cheap, over-the-counter tests, and accelerating the regulatory-approval process. Simply sitting back and letting the market do its work, Mina and his allies argue, is wasting time and costing lives. The Trump administration insists that further government intervention in the testing market is neither necessary nor appropriate. But President-elect Joe Biden has a plan that includes pushing harder for rapid testing. Whether he’s able to carry it out could determine the course of the pandemic.
he most common at-home rapid tests that Mina and others envision are what are called antigen tests—strips of paper that have monoclonal antibodies printed on them that attach to the virus if it’s present, turning the paper a darker color. These aren’t the polymerase-chain-reaction, or PCR, tests clinicians use to diagnose people with COVID-19. Although PCR tests look for any recent sign of the virus, antigen tests hunt for live, infectious virus. “In other words, PCR testing is like a detective at a crime scene, looking for any evidence that a crime is or was in the past few weeks committed,” Mina said. “An antigen test is more like a security guard, looking only for an actionable crime, currently being committed.” (The company Abbott has designed a rapid test called the BinaxNOW, but it is approved only for use by health-care providers. Other companies, such as Lucira, are working on at-home rapid tests that don’t rely on antigens. More on those tests later.)
Although these rapid tests are not very sensitive to the presence of any virus, their proponents say that they catch the people who are most likely to be contagious. Think of these tests like a pregnancy test, but for COVID-19. Just like you would get a pregnancy confirmed by a doctor if you test positive, you would confirm your COVID-19 at-home antigen test either by taking a different type of antigen test or by getting tested at the doctor. “Think about the number of situations where you would love to have something like that,” says Jeff Huber, the president of OpenCovidScreen, which is running a contest for companies to invent a better COVID-19 test. “There was a death in the family and you want to have a funeral and you want people to come together, but you want to do that as safely as possible.” School, work, and even weddings could be back on—even if not everyone had been vaccinated yet.
But some experts say the FDA has been slow to approve these tests. Typically, the agency approves new coronavirus tests based on how well they detect the presence of the virus—and how well they don’t erroneously flag negative cases. Rather than hold antigen tests to that standard, the FDA should approve these tests based on how well they catch people with high levels of virus in their system, Mina argues. The current standard has “turned a lot of the companies off for many, many months, from even submitting anything,” Mina said.
A company called E25Bio, in Cambridge, Massachusetts, has already developed such a test. It costs less than $10, and it provides results in three to 10 minutes. To use it, you swab your nose, place the swab into a liquid, and drop the liquid on a paper strip housed inside a plastic cassette.* On November 10, the company told me it had an application in for approval with the FDA, and had been waiting for several weeks to hear back.
Eric Topol, a cardiologist and the director of the Scripps Research Translational Institute, has gotten the sense that the FDA thinks antigen at-home tests will be too confusing for everyday people to use, and thus will lead to chaos and the erratic reporting of positive cases.
In an interview with Topol for Medscape, FDA commissioner Stephen Hahn said, “it’s a whole different level with at-home tests because there won’t be a provider that’s providing information and guidance to someone who’s doing this at home. We need to make sure that they’re easy to use, easy to understand, and highly reliable.”
In response to a request for comment, a spokesperson for the agency said, “The role of the FDA is to ensure the safety and efficacy of diagnostic tests when used by the intended user. In the case of at-home tests, we assure they are easy for consumers to administer and the results are clear for consumers to interpret … The FDA wants data to show that consumers can also get accurate results and interpret them.”
The agency added that “a developer could opt to validate their test by demonstrating its ability to detect people who are likely infectious. However, that may be more difficult to demonstrate than the validation approach we’ve recommended because there isn’t an accepted way to measure it.”
Another problem that Mina and others point to is that the Trump administration has failed to infuse money into at-home testing companies.
The companies producing these antigen tests, with the exception of Abbott, are small start-ups. The government is essentially waiting for these underdogs to independently raise cash and develop tests, then weighing whether it’s willing to approve them. “If somebody was bombing us, killing even a fraction of the number of people who have died at the hands of this virus, we would not be sitting idly by and saying, I wonder who’s going to make the next crop of missiles for us to use to defend ourselves?” Mina said.
The federal government, he and others argue, should be throwing money at companies to produce the tests, or possibly even building factories to produce them itself. With $20 billion, Mina argues, the government could build four factories that produce enough antigen tests to stop most outbreaks in the country. That may sound like a lot of money, but it’s just 1 percent of the COVID-19 stimulus package, the CARES Act. And after the pandemic ends, the factories could be repurposed for flu tests and other efforts. “But they haven’t done it, and I don’t know why,” Mina said.
One way for the federal government to get affordable, at-home tests to Americans faster would be to use the Defense Production Act, which allows the government to prioritize the manufacturing of goods and infrastructure deemed essential to national security. Though Trump used the act occasionally throughout the pandemic, some, like Mina, say he should have been using it to ramp up at-home testing.
Multiple experts shared Mina’s concern that the government has not already churned out rapid tests. “They kept saying to me, ‘We don’t want to use the [Defense Production Act]; the market will work,’” one person who is working on testing strategies and has had conversations with the Trump administration told me. But once a vaccine for the coronavirus becomes widely available, the market for the tests will diminish, if not disappear entirely. Small companies aren’t eager to put up their own capital for a type of manufacturing that won’t be useful in eight months.
This person got the impression that Trump administration officials were under pressure from the White House not to use the DPA for the production of tests, only to buy up tests that are already available. In August, for instance, the Trump administration bought 150 million rapid tests from Abbott and distributed them to states, colleges, and nursing homes. Mina and his ilk argue that’s not enough—the government should become a manufacturer, and make the test printer go brrr.
Before the election, I asked Peter Navarro, the assistant to Trump for trade and manufacturing, whether the president planned to use the DPA for the production of at-home tests if he was reelected. “Companies along the supply chain working with Abbott understand the power of the DPA—which we have used more than 100 times—so it need not be explicitly invoked to get the desired effect,” he told me.
A spokesperson for Biden’s campaign told me the president-elect plans to use the DPA to scale the production of at-home tests. Vivek Murthy, the former surgeon general under President Barack Obama, will co-chair Biden’s COVID-19 task force. In a recent interview with NPR, Murthy said, “[Biden] wants to expand our testing capacity … not just diagnostic testing, but also screening testing so that we can better open up schools and workplaces.”
There are some pleas for caution on at-home tests, even among their boosters. Topol, from the Scripps Research Translational Institute, argues that we first need a large clinical trial to show that the tests are effective at stopping outbreaks. The test that does so, then, could set the standard for others like it.
Other experts say that imprecise, at-home tests are a terrible idea. Michael Osterholm, the director of the Center for Infectious Disease Research and Policy at the University of Minnesota, worries that if the country is awash in tests that return too many incorrect results, people will lose confidence in testing. They might refuse to get tested, refuse to self-isolate if they test positive, or get PCR and antigen tests mixed up. After the federal government gave nursing homes some antigen rapid tests, the state of Nevada ordered the homes to stop using them once they were found to have an error rate of nearly 60 percent. Another rapid test made by the company Quidel was found to detect only 32 percent of the positive cases identified by a PCR test. (Part of the explanation for the delayed development of cheap, at-home testing might be the mixed messages experts are sending on the effectiveness of at-home tests.)
Osterholm and others are concerned that if people start testing at home, positive cases might not be reported back to public-health departments. Advocates of at-home tests say they should come with apps that people can use to report their results anonymously to their local health department.
The point of rapid testing is not to stop all cases, proponents argue, but to reduce how many there are. People would still have to take precautions, but they would have an extra measure of security knowing they are (likely) not contagious.
What’s more, different types of tests could be used in tandem. A positive antigen test could be confirmed with a PCR test, or one antigen test could confirm a different kind of antigen test. (This type of confirmation is similar to what happens with positive HIV antibody tests.) “We don’t have enough money to do PCR in everybody, every day,” says Mara Aspinall, a biomedical-diagnostics professor at Arizona State University. In the case of a positive antigen test at a nursing home, for example, “if you have to send a nurse home for a day, before you get a central-lab PCR test, it’s a small price to pay. It’s not ideal; it’s logistically a hassle. But it’s a lot cheaper than an outbreak.”
Besides, right now, we’re keeping everyone home because we don’t even know who might have the coronavirus. There is no “perfect,” these experts argue, and the alternative is bad. “Knowing more is better than knowing less,” says Paul Romer, a Nobel Prize–winning economist and an advocate for this kind of testing.
To help people understand the risks of false positives and negatives, Mina said, the U.S. needs a major public-education initiative paired with the tests. People should be told what their results mean, and how to incorporate them into their already-careful lifestyles. “The NIH and the CDC should be hiring, for whatever cost it takes, Coca-Cola’s branding team,” to show people how to use the tests, Mina said.
If the government remains reluctant to fund antigen tests, it could funnel money into other types of tests instead. Sherlock Biosciences, another Cambridge-based company, is working on a molecular test that’s similar to a PCR test but can be performed at home. It will be slightly more expensive—about $20 to $30 a test—but the results would still take only half an hour.
But because of the challenge of getting investors to throw money at a temporary public-health risk, Sherlock will not have the tests out in wide circulation until the middle of next year. The company could get it out sooner, but that would require getting money from the federal government, CEO Rahul Dhanda told me. And so far, that money hasn’t come.
Dhanda told Trump’s coronavirus task force about his company’s plans a few months ago. But “it didn’t lead to a response,” he recalled. “It just sort of fizzled. We never really heard back.”
* This article previously mischaracterized E35Bio's at-home testing process.