Use of saliva at heart of Spit Queen’s new approach to public health surveillance

Dr. Anne Wyllie is renowned for her work developing tests to detect SARS-CoV-2 in individuals suspected of COVID-19 using saliva as a reliable sample type. Her innovative research has played a pivotal role in the development of a cost-effective, fast, and accurate COVID-19 test called SalivaDirect™, for which Wyllie has earned the moniker of the 'Spit Queen' within the clinical diagnostics industry for her exceptional contributions.

On the back of the success of the saliva direct approach, Wyllie’s work is making a substantial impact on outbreak response and public health diagnostics. It has embarked on a pioneering new framework that secured Emergency Use Authorization from the US Food and Drug Administration (FDA) for the SARS-CoV-2 assay. This centralized approach has significantly diminished regulatory hurdles for laboratories and greatly expedited the testing process.

Wyllie has propelled the use of saliva as a reliable and efficient sample type for COVID-19 testing. With SalivaDirect, Wyllie’s contributions have not only aided in advancing the fight against the COVID-19 pandemic but could have the potential to be applied to other clinically relevant diseases in the future.

The conclusion of the COVID-19 pandemic has led to outbreaks of other common respiratory viruses resulting from the lifting of lockdown measures that previously suppressed their spread. As such, Dr. Wyllie's team has commenced investigations to assess SalivaDirect's efficacy in detecting these pathogens, including influenza, human metapneumovirus, and respiratory syncytial virus. Encouragingly, their initial findings have shown positive results.

The pivotal idea of using saliva as a sample type for testing for COVID-19 struck during the peak of the pandemic in 2020, when there was a dire shortage of swabs due to overwhelming demand. Responding swiftly, Yale University established the Yale IMPACT biorepository to collect samples from COVID-19 inpatients and asymptomatic healthcare workers. Wyllie's Ph.D. thesis had already shed light on the superior sensitivity of saliva sampling for detecting pneumococcus bacteria compared to nasopharyngeal swabs. Building on this foundation, a comprehensive study was initiated to compare the detection of SARS-CoV-2 RNA in saliva samples versus nasopharyngeal swabs.

The results showed that saliva samples performed well against nasopharyngeal swabs in COVID-19 detection, setting the stage for the development of a cost-effective and easily accessible testing solution¹. The Yale team, led by Wyllie, spearheaded the creation of SalivaDirect, a streamlined COVID-19 test that revolutionized the diagnostic process. With the assistance of external partners and the American National Basketball Association (NBA), Dr. Wyllie and her team devised a protocol that was submitted to the FDA, who then granted SalivaDirect Emergency Use Authorization (EUA) on August 15, 2020. SalivaDirect is an RNA-extraction-free PCR test designed to work with various PCR instruments and a wide range of reagents.

By eliminating the laborious and resource-intensive RNA extraction step and replacing it with a simplified workflow, the team simplified the standard PCR test. Paired samples were collected and compared for SARS-CoV-2 detection, with saliva proving to be highly promising. Yale conducted an evaluation of 58 studies comparing SalivaDirect to nasopharyngeal swabs and found the majority showed the saliva collection method to be at least equal to, and if not better than nasopharyngeal swabs for SARS-CoV-2 detection¹.

From swabs to saliva

Wyllie's journey towards transforming COVID testing began with her Bachelor's degree in immunology and microbiology and a Master's in cancer immunology from the University of Auckland, followed by a Ph.D. in medical microbiology at Utrecht University and nearly a decade studying spit samples prior to the emergence of the COVID-19 pandemic. Her invaluable experience led to her becoming a research scientist at Yale School of Public Health, where her focus remained on improving the detection of respiratory pathogens.

Join SelectScience^® CEO, Kerry Parker, as she speaks in depth to Wyllie in this latest episode of our podcast series, ‘The Accelerating Science Podcast by SelectScience’. Learn the full story behind the development of the SalivaDirect PCR protocol which propelled Wyllie’s global mission of affordable, high-quality testing programs for all communities in need. Discover how the American NBA helped with this mission and why we should be challenging the status quo in clinical testing.

Listen to 'Open-source impact in saliva testing: How Dr. Anne Wyllie’s work is empowering communities' here!

References

https://ysph.yale.edu/salivadirect/resources/saliva-vs-swabs/