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FDA Approves New Saliva-Based Coronavirus Test Developed At Wash U

A scanning electron microscope image shows the novel coronavirus (yellow) against human cells (pink.) 2-27-20
A scanning electron microscope image shows the novel coronavirus (yellow) against human cells (pink).

The federal Food and Drug Administrationhas approvedthe emergency use of a saliva-based coronavirus tests developed by Washington University genetic scientists.

The emergency use authorization allows companies to sidestep the usual FDA approval process during emergencies and pandemics.

The tests will be ready for the public to use in approximately one month, said Jeffrey Milbrandt, head of Washington University's Department of Genetics and the McDonnell Genome Institute. In the meantime, the scientists are planning to use it to screen employees and students as they return to campus for fall semester.

The scientists developed the tests with the medical supply company Fluidigm, which specializes in equipment that processes and analyzes very small amounts of fluid.

Because the saliva test uses small amounts of both spit and chemicals to prepare the samples, it’s not as vulnerable to supply chain shortages that have plagued other types of testing, Milbrandt said.

It also doesn’t require expensive reagents, can be processed in large batches of 200 samples at a time, and is more comfortable than the popular test that uses a long nasal swab, he said.

Original story from July 9:

Washington University scientists have developed a test for the coronavirus that uses a patient’s saliva instead of a sample from deep inside their nose.

A saliva-based test is easier and less taxing on patients, which means they could seek tests more often and eventually test themselves. It is also cheaper because it doesn’t require as many materials as other coronavirus tests,  the researchers said.

Scientists at Washington University’s McDonnell Genome Institute developed the test with the California-based company Fluidigm, which manufactures diagnostic testing machines and other medical equipment.

Fluidigm last month submitted an emergency use authorization request to the federal Food and Drug Administration. Such an authorization allows companies to sidestep the usual FDA approval process during emergencies and pandemics. The FDA could also require more testing or research on the process before it decides on approval, company officials said.

To complete the test, small amounts of saliva are gathered in a test tube, pre-treated and then run through a machine that can process nearly 200 samples at a time.

“The [test] is accurate, efficient, it uses a noninvasive sample type, saliva,” said Dr. David King, Fluidigm vice president of research and development, during a company seminar on Wednesday.

Researchers at the Genome Institute decided to create a test using saliva after seeing labs hamstrung by shortages of chemicals and swabs needed for other tests. Limited supplies of testing materials hindered the country’s response to the pandemic earlier this year.

Anyone who has received a coronavirus test with a longnasopharyngeal swabknows how uncomfortable the process is, said Richard Head, director of the Genome Technology Access Center at the Genome Institute.

“We were interested in something that would allow for serial testing, meaning repeated tests with something other than NP swabs, which we know are very uncomfortable,” he said. "This is something we thought would be much more comfortable for serial testing.”

Head said eventually a lab could conduct thousands of the saliva tests within a day.

If the test wins federal approval, businesses could someday use the technology to see who is able to go back to work safely without a risk of infecting others, King said.

The FDA has authorized other saliva COVID tests from other manufacturers. In some, patients drool into a test tube, because spitting could spread contagious particles through the air.

The diagrams for the Fluidigm test show a funnel affixed to a test tube that could collect the saliva.

Follow Sarah on Twitter:@petit_smudge

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Sarah Fentem is the health reporter at St. Louis Public Radio.