A new saliva-based COVID-19 is less invasive than many of the traditional nasal swab tests in use, and researchers say it is sensitive, specific, and can deliver results at a lower cost. Based on trials conducted thus far, the test appears to have a high level of sensitivity similar to or more sensitive than other top-performing saliva tests on the market — meaning the test is better able to comparably detect the level of viral load in the sample. This is particularly helpful in gauging infectivity and possibility for spread.
The test uses branched DNA assay technology. Although PCR-based tests receive high marks for their sensitivity, they also require extraction of the nucleic acids, access to thermocyclers and other sophisticated lab equipment not as readily available outside of the United States.
The researchers are launching a clinical trial as part of the final phase of data collection and validation in preparation for an Emergency Use Authorization submission to the U.S. Food and Drug Administration. The team believes the test will be one of the few assay tests that could be made globally available.