The test kit was developed by a Rutgers University laboratory, called RUCDR Infinite Biologics, in partnership with Spectrum Solutions and Accurate Diagnostic Labs.
The agency has come under fire in recent weeks for allowing myriad companies to offer diagnostic and antibody tests without submitting timely data for review, under its emergency use authorization policy because of the pandemic. Tests have varied widely in terms of their accuracy, and access to diagnostic testing has been scattered, with shortages of tests and the materials required to process them straining capacity from one state to another.
To date, 8.1 million people in the United States have been tested for the coronavirus. But public health experts like Dr. Anthony Fauci, the nation’s leading infectious disease expert, said testing needed to double by the end of May.
Just last week, the F.D.A. ordered dozens of companies it had allowed to market antibody tests, which some states and public health experts hope will help indicate the depth of infection in communities and quantify who has recovered and perhaps developed some immunity, to submit data proving accuracy within 10 days, or it warned the products could be removed from the market.
The F.D.A. said that Rutgers had submitted data showing that testing saliva samples collected by patients themselves, under the observation of a health care provider, was as accurate as testing deep nasal swabs that the health professional had collected from them. The agency also said the spit collection kits should be limited to people who are exhibiting Covid-19 symptoms.
“A patient can open the kit, spit into the tube, put the cap back on and ship it back to our lab,” said Dr. Andrew Brooks, chief operating officer and director of technology development at RUCDR. “We bring the test to the patient, instead of the patient to the test.”
The F.D.A. said it still preferred tests based on deep nasal samples, which involve a health professional inserting a long swab up through the nose and into the back of the throat. But even those have had problems. In mid-April, for example, an unnamed team of health providers reported to the F.D.A. that the new Abbott ID Now test failed to detect coronavirus on six patients who were known to have Covid-19.
Rutgers has 75,000 of the saliva test kits ready to ship and can process 20,000 tests each day, with a 48-hour turnaround. Dr. Brooks said he expected other labs around the country to adopt it for their own use.
He said that the Centers for Medicare and Medicaid had approved a $100 fee per test, but prices will vary. One company, Vault Health, is now offering telehealth appointments in which a health practitioner supervises the spit test via video. Vault charges $150 per test.
The spit tests are part of an emergency pandemic response effort by the F.D.A. to help developers of novel tests for the coronavirus quickly get to market. Last month, the agency authorized the first type of at-home kit for the virus in the United States, a kit sold by LabCorp that enables people to swab their own noses and send the samples to be tested at the company’s labs around the country.
Now, at a time when some states say they are still facing a shortage of tests, the at-home spit-collection kits have the potential to widen the audience for virus screening. By keeping people with symptoms at home, instead of asking them to go to medical centers to be tested, the spit kits could reduce the risk of spreading the infection to health care workers.
They may also appeal to people who would feel more comfortable spitting into a container than inserting swabs into their noses to collect virus specimens.
“This combines the ease of saliva collection with at-home collection,” Dr. Stephen Hahn, the F.D.A. commissioner, said in an interview on Friday.
Some public health experts, however, have cautioned that at-home sampling kits can also come with downsides. One is that it can take longer for people to get test results when they use at-home kits that need to be sent to labs. Because the infection can take several days to develop, they said, the time lag could result in some people receiving false negative test results for coronavirus. Physicians, they said, should make patients aware of the limitations.
In its emergency authorization for the Rutgers test, the F.D.A. noted that negative test results would not preclude a coronavirus infection and “should not be used as the sole basis for patient management decisions.”
The agency also noted that the Rutgers lab was the only entity it had authorized to market at-home coronavirus self-sampling kits for saliva. In March, the F.D.A. cracked down on several health start-ups that had rushed to market unauthorized at-home kits that involved consumers collecting their own spit or throat swabs for testing.
“This is not a general authorization,” the F.D.A. said of the Rutgers spit kits, “for at-home collection of patient samples using other collection methods, saliva collection devices, or tests, or for tests fully conducted at home.”
The F.D.A.’s decisions to issue more than 100 emergency use authorizations has drawn intense criticism from Democratic lawmakers. Earlier this week, Senator Elizabeth Warren, of Massachusetts, and Senator Patty Murray, of Washington, both Democrats, sent a letter to Dr. Hahn requesting information on how the agency was tracking the use, safety and effectiveness of Covid-19 treatments. and diagnostic tests given emergency use authorization because of the pandemic.
The lawmakers said they were particularly concerned about the F.D.A.’s tracking of adverse events caused by hydroxychloroquine, a treatment repeatedly promoted by President Trump.
The senators noted evidence of the drug’s lethal cardiac side effects and its lack of evidence as a treatment for Covid-19. “There are also reports that the F.D.A. lowered its quality-control standards so that the administration could accept Bayer Pharmaceutical’s donation of millions of hydroxychloroquine tablets for distribution,” they said.
The senators also told the F.D.A. to make sure that it tracked all reports of adverse events from remdesivir, which received emergency use authorization to treat patients hospitalized with Covid-19.