To speed coronavirus testing, FDA greenlights a new type of nasal swab

One of the biggest bottlenecks in testing people for the novel coronavirus has not involved complex machines to detect genetic material or molecular biology. It’s been a shortage of swabs to take samples.

On Thursday, the Food and Drug Administration announced that it would allow a broader range of swabs to be used in tests, including some made of polyester that should be far easier to manufacture.

“This action today demonstrates the ingenuity that results from FDA working in partnership with the private sector,” FDA Commissioner Stephen Hahn said in a statement. “The Trump Administration has been working side-by-side with our industry partners to fight this pandemic, and today is a great example of that work.”

The FDA also announced that US Cotton, the country’s largest manufacturer of cotton swabs, has developed a polyester-based swab fully compatible with Covid-19 testing. The firm plans to manufacture the swabs in “large quantities,” the FDA said.

Experts hope the moves will make the swabs “so cheap and accessible that we can make them available to anybody as soon as they have a cold-like illness,” said Dan Wattendorf, a physician who directs innovative technology solutions at the Bill and Melinda Gates Foundation, which gave technical advice on the studies that led to the decision.

The FDA on Thursday took other steps that could help speed up diagnostic testing. It now says that a sample can be collected simply by circling the swab in the nose, instead of sticking a longer swab much deeper into the throat through a nostril. That process is deeply uncomfortable and causes patients to sneeze, meaning that health care providers need to be wearing full protective gear.

The agency also said the swab can be done by a patient, instead of by a health care professional. And instead of being stored in viral transport media, a special solution that is in short supply, the FDA also now said that it is OK to use saline solution, which is much more readily available, if necessary.

“That’s really breaking down a lot of barriers when people have shortages,” said Ken Ehlert, the chief scientific officer of UnitedHealth Group, which conducted studies that led to the regulatory changes. “If you look at New York, they were days from being out” of basic materials like swabs and viral media, he said.

Yuan-Po Tu, a physician at the UnitedHealth Group-owned Everett Clinic in Everett, Wash., worked with the Gates Foundation to run studies on how various testing swab techniques compared. Quantigen, a diagnostics firm, was also involved in the study, the results of which were announced simultaneously with the changes in FDA policy.

Tu said the research has shifted how he practices at his clinic, where he now tests patients in their cars, having them swab their own noses.

“This can be done very quickly in our drive-through,” Tu said. “We can collect one person every three minutes. When we do it in a car, we’re using the car as the containment vehicle. It’s not only faster, it’s nicer and more user-friendly and it’s much safer for everybody involved.”

The material used in the swab can affect testing. The tests work by growing large amounts of the virus using a reaction called the polymerase chain reaction, or PCR. Q-tips, for instance, don’t work, in part due to the fact that the cotton on the tip contains its own DNA; cotton, after all, is a plant. The swabs that are currently used are nylon or foam. But the FDA’s expansion of permitted materials to some made of polyester could help reduce shortages.

Wattendorf, the Gates Foundation director, said that over the next few days he expects data on whether tests are still accurate after they are exposed to temperature extremes that would likely occur when sent through the mail. That could be a step toward the FDA allowing tests that people can send to diagnostic laboratories through the mail.

The 330 million people in America have about a billion colds each year, Wattendorf said, and testing returning to a semblance of normalcy could require running tests on many of them. Making sure there are enough swabs is an important step to making that happen.

“It’s really important the world knows about it,” Wattendorf said. “We want the manufacturers to know about it, we want the doctors to know about it.”