Anne L. Wyllie ^1* Brittany Choate ² Laura Burke ^2* Yasmine Ali ^2*

• ¹ School of Public Health, Yale University, New Haven, Connecticut, United States
• ² SalivaDirect, Inc., New Haven, United States

The COVID-19 pandemic caught the world unprepared. Large-scale testing efforts were urgently needed, and diagnostic strategies had to rapidly evolve in response to unprecedented worldwide demand. However, the roll-out of testing for SARS-CoV-2 was often impeded by logistical challenges, including regulatory delays, workforce shortages, laboratory bottlenecks and supply chain disruptions. Recognizing these hurdles early on, we developed a testing approach for frequent, repeat testing, particularly as communities reopened. We hypothesized and experimentally demonstrated that saliva was suitable for the detection of SARS-CoV-2. This finding was advanced into the development of extraction-free RT-PCR protocols using readily available, “off-the-shelf” reagents and equipment for streamlined detection of SARS-CoV-2 in saliva (“SalivaDirect''). Working with the US FDA, we established a novel regulatory framework; the FDA granted Emergency Use Authorization to Yale University to offer the SalivaDirect protocol to high-complexity CLIA diagnostic laboratories with quality oversight provided by Yale. This grew into a network of >200 designated CLIA labs across the US that, as of May 2024, resulted in over 6.5 million SARS-CoV-2 tests. By making the protocol flexible and open-source, laboratories were able to rapidly and economically scale testing using a simple, self-collected saliva specimen. Additionally, fostering a nationwide network of laboratories enabled real-time exchanges, problem-solving, and the development of community best practices. Preparing for the next pandemic, or simply the next seasonal epidemic, the SalivaDirect model of deploying a readily available, expandable solution and accompanying laboratory network provides a proven method for the successful implementation of pathogen testing in the US and globally.