Coronavirus saliva tests could be cheaper and faster. Here’s how they work

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Taking one of the latest coronavirus tests to gain federal approval is as easy as spitting.

SalivaDirect, developed by researchers at the Yale School of Public Health, was granted emergency approval by the Food and Drug Administration on Saturday and offers a more comfortable alternative to a nasal swab. Saliva can be collected in any sterile container.

As the United States grapples with building testing capacity to meet the growing demand brought on by people resuming school and work, officials have placed their hopes on several solutions including saliva testing. Since the test doesn’t require chemical reagents or swabs that have become scarce during the pandemic and offers a faster turnaround than the standard test, some believe it could offer the country a way to determine the spread of the virus quickly.

“Providing this type of flexibility for processing saliva samples to test for covid-19 infection is groundbreaking,” said FDA Commissioner Stephen Hahn in a statement.

The Yale team’s research, which has not been peer-reviewed, was funded by the NBA. The league uses SalivaDirect to test asymptomatic players and staff in its bubble, a quarantined zone for teams at Walt Disney World in Florida. Comparing the results of saliva tests to the more common method, called polymerase chain reaction, or PCR, the scientists found that the test was just as accurate.

While SalivaDirect isn’t the first saliva test to get the green light from the FDA, its efficiency could improve the bevy of tests coming to market. According to Yale, its approach goes beyond what the four previously approved saliva tests could, allowing labs to skirt supply chain concerns for reagents by validating multiple vendors.

The research team is already working with other labs to get more tests authorized, Chantal Vogels, a Yale postdoctoral fellow who led the laboratory development and validation of the test, told The Washington Post.

One of the research groups is led by Martin Burke, a chemist at the University of Illinois at Urbana-Champaign who has already launched a similar saliva test he developed at the university’s campus to screen more than 50,000 students, faculty and staff members. The test’s quick turnaround time has allowed the school to reach its goal of 20,000 tests per day, or its aim to test students twice per week, Burke told The Post.

Millions of students are returning to college campuses this fall, and some have already been sent home because of outbreaks. As schools have wrestled implementing coronavirus precautions and screening, Burke believes the speed and affordability of the saliva test could be scalable for others – if they have the availability of a lab. Frequent testing would can guarantee an infected person is notified and quarantined promptly before passing the virus to peers.

Illinois students can go to one of 40 testing stations across their campus, self-administer the test and get their results on a university-created app within three to five hours, Burke said. The school retrofitted its veterinarian laboratory to handle screening the student population. Burke hopes the capacity will be expanded to offer testing to other people off-campus.

While Burke’s team is still collecting data on the test’s sensitivity, he said that an initial clinical study showed promising results.

Prompt and persistent screening is essential to reducing the “window of transmission,” allowing those who are infected to isolate early before exposing others

“If you look at the goal of surveillance testing, fast and frequent testing is the key,” Burke said.

The test is also cheaper since it doesn’t need some finite reagents. The Yale researchers estimated the test could cost up to $10 to be run.

“Our mission is to remove capitalism from surveillance,” the Yale team’s lead researcher, Nathan Grubaugh, tweeted Tuesday. “We want to make available cheaper tests, and we believe that companies shouldn’t overly profit from this. That is why we offer our protocol for free, and we are working with labs to implement cost and time saving steps.”

Bottlenecking in America’s supply chain and limited lab capacity has plagued the country’s efforts to ramp up testing.

One essential testing component, the nasopharyngeal swabs that are designed for patients’ upper respiratory passage, are not only prone to scarcities but also makes patients uncomfortable.

Instead, the saliva tests allow patients to spit into a container. One test, created at Rutgers University, can even be done at home.

The test also doesn’t require a trained staff member to administer the test, freeing up workers and reducing the risk of exposure.

“One of the most important benefits for using saliva instead of a swab is it’s pretty difficult to take a swab accurately,” Vogels said. “You really need a skilled person, like a health care worker, and if it’s not taking correctly, then you might miss detection of the virus.”

The Yale team has touted its test bypasses extracting virus’s genetic material, another part of the standard screening with supply scarcities.

“Being able to perform a test without these kits enhances the capacity for increased testing, while reducing the strain on available resources,” according to the FDA.

The test still requires analysis at a lab, meaning that it would not hasten the process in areas without CLIA-certified facilities, or places where labs are overwhelmed. But since the test does not require any proprietary equipment, labs with varied operations could run these tests “provided they comply with the conditions of authorization in the EUA,” according to the FDA.