As people increasingly return to schools, sporting events, concerts, and other public gatherings, it's more essential than ever to have fast, low-cost, easy COVID-19 testing, said Anne Wyllie, associate research scientist in epidemiology at Yale School of Public Health (YSPH).
One pathway to meeting this challenge is SalivaDirect™, an innovative and cost-effective saliva-based COVID-19 test developed by a team led by Wyllie and Nathan Grubaugh, an assistant professor at YSPH. SalivaDirect uses saliva samples which can be easily collected and involves fewer resources than nasal tests, a process that requires, among other materials, swabs and expensive preservatives. In addition, saliva samples can be tested using equipment and reagents found in most labs at a much lower cost.
As of this week, 100 labs in 36 states are set up to run SalivaDirect testing. The team's goal is to make the protocol available to as many labs as possible to improve the accessibility of COVID-19 testing.
"We have seen this grow from simply a test for COVID-19 into a collaborative network of testing labs," said Wyllie.
Each week, Syllie said, the Yale team leads a call with participating labs and those looking to be involved. These ongoing discussions, which typically attract more than 50 labs, has become a forum for sharing information and addressing questions.
Like other COVID-19 tests, SalivaDirect was authorized by the U.S. Food and Drug Administration under emergency use authorization. But what differentiates SalivaDirect from the swab-based methods is it is accessible for many additional small labs, said Wyllie. More communities across the country can offer local testing, she said. And since samples don't have to be sent to larger testing labs, sometimes at great distance, it enables a more efficient turnaround at a lower price.
"We are empowering local community labs," said Wyllie. "It will be a lot easier for communities to get samples to these nearby labs and to get same-day results."
The Yale team demonstrated that their saliva-based test was as effective as swab-based testing during a partnership initiated last summer with the National Basketball Association (NBA), in which they collected and analyzed more than 3,700 saliva samples from players and league associates during the 2020-21 NBA season. They demonstrated very low rates of invalid (0.3%) and false-positive (0.03-0.05%) results, demonstrating the validity of the SalivaDirect method.
Even as vaccine access increases, Wyllie said, testing will remain crucial. "Younger individuals are not eligible for vaccines until later, and there are those who can't get vaccinated," she said. "Also, testing is essential for monitoring variants as they emerge."
In addition to SalivaDirect's usefulness in the U.S., Wyllie said the ease of saliva collection, the simplicity of the testing protocol, and the fact that cold chain transport is not required means that SalivaDirect is also a valuable option in regions worldwide that lack resources.
