Clinical laboratories can perform a new saliva COVID-19 test with a wide variety of existing reagents and equipment.
The US Food and Drug Administration (FDA) announced Aug. 15, 2020, the grant of an emergency use authorization (EUA) for a new saliva-based SARS-CoV-2 diagnostic test. The EUA was issued to Yale School of Public Health for its SalivaDirect COVID-19 diagnostic test, the fifth test authorized by the FDA for use on saliva specimens.
The SalivaDirect COVID-19 diagnostic test is unique from other saliva-based COVID-19 tests because it does not require a separate nucleic acid extraction step. According to the FDA press release, “Being able to perform a test without these kits enhances the capacity for increased testing, while reducing the strain on available resources.”
No swabs or specific collection devices are needed for this test, and the specimens can be collected in any sterile container. “The SalivaDirect methodology has been validated and authorized for use with different combinations of commonly used reagents and instruments, meaning the test could be used broadly in most high-complexity labs,” states the FDA in the announcement.
Saliva Promising for COVID-19 Testing
A team at the Yale School of Public Health, that includes Chantal Vogels, PhD, MSc, BSc, (left, above), Doug Brackney (above, right), and others, notes the flexibility to ease medical laboratory supply chain stress with the new SalivaDirect COVID-19 open source diagnostic test, which received an emergency use authorization from the FDA in August 2020. (Photo source: Yale School of Public Health)
The Yale open source saliva coronavirus test is considered a major step toward broad SARS-CoV-2 testing. “This started off as an idea in our lab soon after we found saliva to be a promising sample type of the detection of SARS-CoV-2, and now it has the potential to be used on a large scale to help protect public health,” said Chantal Vogels, PhD, MSc, BSc, a Yale Postdoctoral Fellow, who led the laboratory development and validation, along with Doug Brackney, a Yale adjunct Assistant Clinical Professor of Epidemiology, Microbial Diseases.
“Providing this type of flexibility for processing saliva samples to test for COVID-19 infection is groundbreaking in terms of efficiency and avoiding shortages of crucial test components like reagents,” said FDA Commissioner Stephen M. Hahn, MD. “The FDA encourages test developers to work with the agency to create innovative, effective products to help address the COVID-19 pandemic and to increase capacity and efficiency in testing.”
Yale COVID-19 Saliva Test Flexibilities
This test allows broad flexibility in collection containers and elimination of the nucleic acid extraction step. When coupled with the wide range of reagents and instruments permitted in the EUA, this test provides a great deal of flexibility for clinical laboratories that may be experiencing strains on resources or supply chains.
In a press release by Yale, Yale reports that researchers “are not seeking to commercialize the method. Rather, they want the simplified testing method to help those most in need. Testing for SARS-CoV-2 has been a major stumbling block in the fight against the pandemic, with long delays and shortages of testing. Some experts have said that up to 4 million tests are needed per day; SalivaDirect provides one pathway toward that goal.”
What Open Source Means to COVID-19 Testing Laboratories
The FDA notes that Yale intends to offer the protocol for the SalivaDirect COVID-19 diagnostic test as an “open source” protocol, allowing clinical laboratories to use the test without having to rely on proprietary equipment from Yale. This permits laboratories to use any of the many commercially available testing components that are permitted under the EUA.
Clinical laboratories that are facing supply chain shortages may especially benefit from this test, given the wide range of reagents and equipment that can be used to implement it. Eliminating the need for unique test collection equipment further reduces potential supply strain.
—By Caleb Williams, Editor, COVID-19 STAT