En español | Eleven days after she went to get a coronavirus test, Washington, D.C., resident Megan Bishop was still waiting for her results. An email reply from the public testing site informed her that they weren't ready yet, and to expect delays during times of increased demand.
Eight days later, she still didn't have an answer. Bishop eventually learned that a technical glitch was responsible for the slowdown. Nearly a month after she went to get tested, she received her results: negative for COVID-19.
Despite improvements since the beginning of the coronavirus pandemic, people across the country have recounted similar experiences with the testing process, receiving their lab results long after the 10-day period of self-isolation recommended by the Centers for Disease Control and Prevention (CDC) for positive cases. And it's a system that epidemiologist Michael Mina said isn't doing “much good” when it comes to halting the spread of the new virus, which so far has infected more than 5 million Americans.
The main reason: Scientists think people infected with the coronavirus (SARS-CoV-2) are most contagious from a few days before COVID-19 symptoms appear till a few days after they start. Meaning that by the time someone gets tested and receives the results, the information is less useful. At that point, the infection may be over and it could have already spread to others, rendering it too late to make effective use of contact tracing — the process of identifying and warning people who may have been exposed to an infected individual.
"We're contact tracing millions of people who don't need to be contact traced because they were actually infectious weeks ago. We're also quarantining millions of Americans for 10 or 14 days who haven't been transmitting for weeks by the time they got their result,” Mina, an assistant professor at the Harvard T.H. Chan School of Public Health, explained on a recent call with reporters. “And this isn't even taking into account the fact that result times are so delayed.”
Instead, he wants to see a testing strategy that doesn't just diagnose cases but also helps to stop them from happening in the first place. And the way to do that, he argued, is with fast, inexpensive and accessible at-home tests that can let people know their infection status on a regular basis — no lab or lab equipment required.
"If we can get a test that everyone wakes up and just like they put in their contact lenses, they take a test, and if it turns positive, they stay at home … it will stop the vast majority of transmission and cause these outbreaks to disappear in a matter of weeks,” said Mina, who has been calling for over-the-counter tests since the beginning of the U.S. outbreak.
"People can act on it because they're getting immediate results."
No lab, no machine
Right now, these tests do not exist. But a groundswell of support from public health experts has pushed the demand for rapid at-home tests to the forefront in recent weeks. In late July, the Food and Drug Administration (FDA) — the federal agency in charge of approving diagnostic tools — posted a template that allows for companies to apply for emergency use authorizations for tests that can be conducted and analyzed in non-lab settings, such as schools, offices and homes. An emergency use authorization allows for expedited approval of a test so it can come to market faster in a public health emergency.
Even so, experts say it's going to take an overhaul of the country's testing framework to get these tests in the hands, and homes, of everyday Americans.
The type of test Mina and other experts are championing is different from the at-home tests currently available, which still require the user to mail a saliva sample or nasal swab to a lab for processing. It's also different from the rapid tests that are administered in health care settings and long-term care facilities to diagnose patients at the point of care. While these tests don't need to be sent away to a lab for analysis, they still rely on health care personnel and on-site instrumentation for results.
Mina likened this type of testing to a Nespresso machine: “There'll be a big start-up cost to get it going, and then each individual test will be expensive,” he said. What he wants to see is something more akin to “instant coffee” for the masses — an over-the-counter test that costs no more than a few bucks a pop and doesn't need a machine to put out a positive or negative reading, similar to a pregnancy test.
The good news is the technology is in place to make these tests a reality in the not-too-distant future. In fact, several companies are working on their development, including Massachusetts-based E25Bio, whose SARS-CoV-2 paper-strip test just came out of clinical trials. It can detect the presence of the virus from a nasal swab in about 15 minutes “and there are no machine parts,” said Carlos-Henri Ferré, E25Bio's director of operations and communications. E25Bio plans to request FDA authorization for the first iteration of its test soon, in hopes of making it available to the public this fall.
Overcoming sensitivity, reporting requirements
But that's where companies making more consumer-friendly tests may run into hurdles. Although the FDA has opened the door for these types of tests to seek approval, Mina argued that the agency's criteria for sensitivity and reporting could make cheap and easy coronavirus tests not so cheap and easy.
For starters, many rapid tests — including the paper test from E25Bio — are antigen tests, which can be less sensitive compared to standard lab-based PCR (polymerase chain reaction) tests. This is because antigen tests, which detect fragments of virus proteins, require larger amounts of virus to be present to generate a positive result, said Ashish Jha, M.D., director of the Harvard Global Health Institute.
PCR tests, on the other hand, detect the virus’ genetic material and can catch an infection even if virus levels are low or lingering after a person is no longer contagious. Current federal regulations require antigen tests to be nearly as sensitive as PCR tests. So far, two “Nespresso model” antigen tests have been granted emergency use authorizations from the FDA.
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But proponents of antigen tests point out that sensitivity is generally not an issue at the time you most want to catch COVID-19 cases. “If you want to identify whether [someone is] infectious and going to go out and spread to other people, these tests are actually quite good,” Jha said on a recent call with reporters. And when used on a regular basis, they “can really start bringing the virus under control in communities.”
The FDA also sees the benefit of making antigen tests more widely available. An agency spokesperson told AARP that while tests with lower sensitivity miss some cases, convenient alternatives can help expand testing availability and increase options for people who might otherwise not get tested.
Tests that you could buy at a drugstore and use at home “will be a game changer in our fight against COVID-19 and will be crucial as the nation looks toward reopening,” Stephen Hahn, FDA commissioner of food and drugs, said in a statement.
The second hurdle that fast at-home testing faces in the current system is the reporting requirement. COVID-19 tests analyzed in labs and doctors’ offices are reported to local and state health departments, and are used to inform reopening policies. Case counts also help experts track where the virus is spreading and where resources are needed most.
Whether a person testing with paper strips at home is “going to actually use that information to stay at home and self-quarantine, whether they will report themselves to the state, whether they will reach out to contacts — all of that is pretty much an unknown,” said Sixto Leal Jr., a pathologist and assistant professor of laboratory medicine at the University of Alabama at Birmingham School of Medicine. “I'm not saying there's not a role for it; there probably is. But like everything with this pandemic, there's a lot of new aspects to it that have to be figured out.”
Some testing companies are looking into apps that could dispatch results anonymously, Vox reports. “Maybe some third parties can get involved and collaborate, but it adds months to the effort of getting these things out and we need them today,” Mina said.
A change in testing could change COVID-19 trajectory
One way to break through these two barriers is to change the whole testing approach for SARS-CoV-2.
Mina and other health experts are lobbying for testing to be thought of less like a clinical tool and more like “a true public health tool” that can be used “to break transmission chains, in the same way that we know that masks can serve to decrease transmission.” Such an approach would help to cut through some of the regulatory red tape that is hamstringing companies capable of developing these tests.
Bishop said that after her latest testing experience, she'd consider using at-home tests if they were available, although she's not out in the community enough right now to justify regular testing. Where she sees their value, however, is among frontline workers.
"I would want those tests to be available for those people who are essential workers or working out in the community,” she said. “But if I were in that situation, yeah, absolutely, I would take them.”
Mina is hopeful that a shift in testing will happen soon — especially since stopping infectious people from spreading the virus “could buy ourselves potentially years of time” in the absence of a vaccine. “It's a tool that can stop infections today,” he added.