Last week, two high-profile San Francisco health start-ups began marketing at-home coronavirus kits that let people collect their own saliva samples or oral throat swabs and then send the specimens to commercial labs to be tested for the virus.
The start-ups, Carbon Health and Nurx, each said they were preparing to offer thousands of the kits in the coming weeks. By Friday afternoon, the Nurx site said its kits had “reached capacity for today” and promised more would be available for sale this week.
But on Friday evening, the Food and Drug Administration issued an alert warning consumers that it had “not authorized any test” for the coronavirus that people could buy and administer at home. Carbon Health and Nurx subsequently suspended sales of their kits.
As the coronavirus pandemic intensified across the country, the two companies and other start-ups rushed to market collect-your-own specimen kits without rigorous published studies proving the effectiveness of at-home swabbing for coronavirus testing.
The dash to sell at-home kits coincided with a push by the White House to promote rapid innovation in coronavirus testing by relaxing federal health regulations. Last Wednesday, President Trump announced that his administration was studying the possibility of introducing self-swabbing on a mass scale — an effort that could free up health providers to focus more on treating seriously ill patients and less on collecting specimens. Then on Monday, the White House appeared to overrule the F.D.A., saying that “self-swabbing options” should be available to Americans this week.
Tech giants and some of their top executives are also racing to help track the spread of the virus and rapidly increase testing. The Bill & Melinda Gates Foundation is sponsoring research at major medical centers on at-home kits.
The studies are examining whether swabbing inside your nostrils with a short Q-tip-like wand at home could work as well for coronavirus testing as the medical-grade specimens that health professionals collect — an often uncomfortable process that involves pushing a long swab up through the nose to collect samples from the back of a patient’s throat.
“There are significant differences between these collection methods,” Dr. Dan Wattendorf, director of innovative technology solutions at the Gates Foundation, said in recent comments on the foundation’s site. “So it’s essential for the F.D.A. to evaluate their relative performance through rigorous, well-designed studies.”
The Gates Foundation and others are optimistic that self-collected swabs might prove effective for the coronavirus. The hope is that the kits could help stem the pandemic by enabling millions of people who are carrying the virus to safely collect their own testing samples without going to doctors’ offices, where they might infect health providers and other patients.
The start-ups were not marketing a novel method of testing for infectious diseases. At-home kits have proved effective for other infections, such as gonorrhea.
Founded in 2015, Nurx markets self-swabbing kits and online consultations for sexually transmitted diseases. The start-up, whose investors include the venture capital firms Kleiner Perkins and Union Square Ventures, said it had worked with Molecular Testing Labs, its longstanding diagnostic testing provider, to develop its coronavirus kits and was confident the tests were accurate.
Executives at Carbon Health, which offers telemedicine consultations as well as in-person medical care at its own clinics, said it had decided to offer self-administered sampling kits after doctors there treated some of the first coronavirus patients in California and ran into obstacles getting them tested. It worked with Curative, a three-month-old start-up, to develop a saliva test for the virus.
“Having a saliva sample that can be mailed back and that is just as accurate, or nearly as accurate, as the nasal or the throat swab was very attractive to us,” said Dr. Caesar Djavaherian, the medical director of Carbon Health.
Another San Francisco start-up, Forward, which runs health care clinics using a health-club-like membership model, announced last week that it was offering self-swabbing kits on a limited basis to members it determined to be at high risk for the virus. Forward’s investors include Joshua Kushner, the brother of Jared Kushner, Mr. Trump’s adviser and son-in-law.
But public health and laboratory medicine experts cautioned that tests based on self-swabbing might not be accurate, noting that many of the at-home kits did not adhere to current medical standards of care.
For coronavirus testing, the Centers for Disease Control and Prevention recommends that health care professionals first and foremost collect nasopharyngeal samples — the ones involving the long swabs through the nose. Experts said that was because there was not yet enough effectiveness data available on testing other kinds of specimens for coronavirus.
The Nurx kit uses oral swabs of the throat, the Forward kit uses inner-cheek swabs, and the Carbon Health kit uses saliva.
“That sounds to me like a really terrible idea,” Dr. Sheldon Campbell, associate director of the Yale School of Medicine’s Clinical Microbiology Laboratory, said of collecting saliva samples at home. “There is concern, in this outbreak emergency setting, that good labs will cut corners and that bad labs will spring up to exploit the opportunity to make a quick buck.”
Last month, the F.D.A. issued guidance for the pandemic allowing accredited commercial labs to develop and perform tests for the coronavirus — as long as they applied for an emergency use authorization from the agency within 15 days of initiating testing.
Carbon Health, Forward, Nurx and Everlywell, another start-up that promoted at-home kits, each said last week that they were working with accredited labs that had received the F.D.A. emergency authorization. They also said the labs met federal standards for demonstrating the accuracy of their coronavirus tests.
But on Friday, the F.D.A. clarified that the coronavirus testing guidelines for accredited labs did not apply “to at-home testing, including self-collection of samples to be sent to a clinical laboratory.”
The also agency noted that it saw the “public health value in expanding the availability” of safe and accurate coronavirus tests that may include home collection. “We are actively working with test developers in this space,” the agency said.
Nurx said on Monday that it had suspended sales of its kits.
In a statement, Carbon Health said it was discontinuing the at-home kits and contacting the 50 people who had used them to schedule testing in its clinics.
Everlywell said it was moving to provide its kits, which use the long swabs for nasopharyngeal testing, to health care providers and hospitals.
Forward did not respond to emails from a reporter.
Researchers working on the Gates-sponsored nasal self-swabbing study said they hoped to have results soon showing the efficacy of at-home coronavirus kits. Among other things, the researchers are studying whether self-administered nostril swabs pick up sufficient cells to produce accurate results.
“One of the things we are trying to figure out is, how accurate is this nasal test going to be?” said Dr. Yvonne Maldonado, a professor of pediatrics, health research and policy at Stanford University School of Medicine who specializes in infectious diseases. “If you are negative, how likely are you to be still infected?”