Nearly two months after federal regulators unveiled rules for at-home coronavirus tests, no company has federal approval to sell these fast and cheap tests even though the technology is ready.
Molecular PCR tests processed at medical labs remain the standard of accurate testing, but they are more expensive and results can take days to process.
Antigen tests are less expensive, plentiful and deliver results in minutes. Three companies gained Food and Drug Administration authorization to sell antigen testing instruments to labs or clinics. A fourth company, Abbott Laboratories, won approval to market a $5 rapid, credit card-sized test administered by a health care professional.
But no company has been cleared to sell tests directly to consumers for widespread screening – a step some believe is necessary to slow the spread of COVID-19, as more than 200,000 Americans have died and people worry about safely returning to work, school, travel or sporting events.
“The way to get this under control is if people find out as early as possible they are infected and then quarantine from others,” said Dr. Yukari Manabe, a Johns Hopkins University professor of medicine.
The United States needs 30 million tests a week to adequately track the virus and protect vulnerable residents, according to the Rockefeller Foundation. Labs have worked round the clock to gradually bring more tests to Americans over the past six months. Still, the nation reached 1 million daily tests for the first time last week, about one quarter of Rockefeller’s goal of more than 4 million tests each day, according to the COVID Tracking Project.
Testing in many states and clinics is limited to people exposed to the virus or sick. Routine screening could prevent the spread among people who have the virus but don’t have any symptoms. If people test themselves before going to work, restaurants or school, it could significantly reduce transmission.
The effort to screen people without symptoms is monumental, said Stephen Tang, president and chief executive officer of OraSure Technologies.
“We’ve never had this kind of undertaking in our history,” Tang said.
Rapid test studies underway
With labs stretched to their limits, the extra capacity must come from companies that make portable antigen tests. Large and small companies alike are working toward that goal.
Post-it Note maker 3M has teamed with MIT researchers to develop a rapid, paper-based test. Researchers said the goal is to develop a point-of-care test to deliver quick results outside a lab. Representatives of 3M and MIT declined to say whether they plan to make a test for consumers to use at home.
Illinois-based Abbott in August became the first company to gain approval of a rapid antigen test using “lateral flow” technology, similar to a pregnancy test. The U.S. Department of Health and Human Services will spend $750 million to purchase 150 million tests with the first shipments expected this month.
The test must be administered by a healthcare professional such as a physician’s assistant or a school nurse. An Abbott spokeswoman declined to say whether the company will seek FDA authorization to sell a home version.
Several other companies are working to bring home tests Americans can purchase without a prescription or doctor’s referral.
OraSure sells a rapid HIV test at retailers such as CVS, Walgreens and Walmart. The company has developed a rapid antigen test now in clinical studies. It expects to sell directly to consumers before the end of 2020.
Gaining FDA authorization for these inexpensive, at-home tests is no easy task.
Under the agency’s template, released July 29, the FDA said at-home tests should correctly identify positive cases at least 90% of the time. This sensitivity threshold is higher than antigen tests the agency has authorized for point-of-care or lab settings.
The agency also wants companies to conduct studies on how tests work on patients. The FDA recommends studies with at least 150 people, of which at least 30 people test positive for the virus.
Two companies, Gauss and Cellex, last week announced a rapid antigen test being studied in clinical trials. Gauss developed an app with detailed instructions for users. Cellex’s rapid antigen test has demonstrated nearly 90% sensitivity, the FDA’s minimum for such tests.
Cambridge, Massachusetts-based E25Bio is studying its antigen test on people without symptoms at a co-working space in the Boston area. The company already has applied to market its rapid antigen test as a diagnostic that can be used at labs. The company wants to gather enough data to apply for at-home testing, said Carlos-Henri Ferré, E25Bio’s director of operations and communications.
Ferré said the FDA’s template for at-home testing requires a sensitivity level higher than other forms of antigen testing.
“If we’re talking about a screening device, the parameters don’t need to be the same as an ultimate diagnostic test,” he said. “We hope the (FDA’s) language would change and reflect what we’re creating, which is a screening tool for public health.”
‘Feels like a big hole’
Experts say PCR tests that detect the virus’s genetic material are the most accurate to detect low levels of the virus. But these tests are processed by labs that need trained workers and sufficient chemical supplies. If there’s a shortage of supplies or workers, test results are delayed. Some major commercial labs took a week or longer to process tests in July, delivering results of little use for consumers.
The antigen tests, which detect proteins, are often less sensitive than PCR tests. But some argue antigen tests, which can produce results in minutes and are less expensive, can identify when a person is infectious and most likely to pass the virus to others.
“From a public health standpoint, the lower sensitivity might not matter if your point is to take people who are infected out of circulation,” Manabe said. “Because you are probably going to find all the people with a relatively high viral load using the antigen test.”
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But the FDA also must evaluate other factors, such as how results from antigen tests are publicly reported to public health officials. State and local health departments might not know when someone tests positive or when to dispatch workers to trace the contact of infected individuals.
More than 20 states could not track or do not disclose data on rapid antigen tests, leaving public health officials unable to know the true spread of the virus, Kaiser Health News reported.
Manabe said the FDA’s existing stance on at-home testing is an “evolving situation” that might require test developers to use an app or cloud-based device to track test results. Still, requiring consumers to log into an app and voluntarily report their test results might be ineffective.
Testing industry officials want to know how the FDA will require test manufacturers to track results
“The big question that is present in the industry is how will at-home approval be viewed by the FDA?” said Anthony Lemmo, CEO of BioDot, a company that testing supplier. “To just go to CVS and buy it without this information being collected, from an epidemiological point of view, feels like a big hole.”
Abbott is pairing its rapid test with a mobile app consumers can use should they need test results to enter places where people gather. The Gauss-Cellex test would require users to take their own nasal swab and scan the rapid test on a mobile app, which would inform the user of the test results.
Peter Pitts, a former FDA associate commissioner and co-founder of the Center for Medicine in the Public Interest, said the FDA must consider the benefits of speed, accuracy and reliability when evaluating any test or product.
“The only thing worse than no data or no testing is bad data based on bad testing,” Pitts said. “It sends us into the wrong direction. It compromises people’s faith in the system and it doesn’t provide anything useful.”
Ken Alltucker is on Twitter as @kalltucker or can be emailed at [email protected]