SalivaDirect –– a saliva-based COVID test that was developed at Yale –– is being explored as a testing tool by schools across the United States. Yale is not among them.
As schools begin to craft public health plans for the spring semester, testing will remain an essential part of keeping campus communities safe. Because SalivaDirect poses fewer exposure risks for healthcare workers, does not incur expenses for nucleic acid extraction and has flexible requirements in terms of equipment and reagents, it has become an attractive possible alternative for several institutions, including Sacred Heart University, Washington State University and New Haven public high schools.
“I know a number of other schools are looking into it or using variations of it,” Anne Wyllie, associate research scientist in epidemiology and one of the leading developers of SalivaDirect, told the News.
One of the biggest advantages of SalivaDirect is the fact that it does not require the complicated RNA extraction process. This step, which isolates COVID-19’s genetic material for detection, is not only typically expensive but also requires a number of specific reagents. According to a survey conducted by the Association for Molecular Pathology, as of August, 81 percent of labs had faced RNA extraction kit shortages during the pandemic.
While most testing methods rely heavily on this RNA extraction approach, SalivaDirect uses a different technique that involves applying an enzyme called proteinase K and heat to the saliva sample. This strategy was found to cause only a minor reduction in the test’s sensitivity — the rate of true positive values — and is significantly less costly than its aforementioned alternative.
In addition, the fact that SalivaDirect does not require a specific container, but rather allows for any sterile recipient to be used, also increases the method’s accessibility. Another notable feature of the test is that its protocol has been made freely available online for other laboratories to use.
“SalivaDirect is a useful tool for university testing and several around the country are using it,” Nathan Grubaugh, assistant professor of Epidemiology at Yale and one of two Yale professors who helped develop SalivaDirect, told the News. “To my knowledge, there isn’t established lab capacity at Yale to do all of our testing in-house, regardless of SalivaDirect or not.”
SalivaDirect is also being used in other settings besides universities. It was used in the NBA bubble, the tightly controlled setting under which NBA players were able to successfully finish the 2019-20 basketball season. According to the New Haven Independent, the testing tool is also being considered for usage in New Haven high schools.
In an email to the News, Dr. Madeline Wilson, chief quality officer of Yale Health and chair of Yale’s COVID Testing and Tracing Committee, wrote that after significant deliberation, the University’s Public Health Advisory Committee landed on the Broad Institute in Cambridge, Massachusetts, as their testing partner. She added that Yale signed a contract with them for the fall semester in early July.
“The Testing and Tracing Committee, in collaboration with the Public Health Advisory Committee for the university, went through a fairly extensive evaluation of testing options during the early summer, several months before SalivaDirect became available,” Wilson wrote.
While SalivaDirect did receive an emergency use authorization from the Food and Drug Administration in August, by then, Yale had already committed to working with the Broad Institute.
According to Wilson, because Yale Health has made significant investments into their partnership with the Broad Institute and is “very happy with their service, turnaround time and reliability.” The commitment will extend into the rest of the academic year.
“While the timing didn’t work out for the university’s testing program, we wish the SalivaDirect team the best of luck in further exploring and extending the use of their innovative assay,” Wilson added.
According to Paul Forscher, professor of Molecular, Cellular, and Developmental Biology, this is a potentially worrisome approach. He told the News that Yale’s current testing system — which is available for all Yalies living in New Haven but only mandatory for undergraduates enrolled in residence and some graduate students, faculty and staff — and contact tracing are “conservative.” He also said that as COVID-19 cases increase, these systems could pose problems for the students, staff and faculty at the University. Forscher called for Yale to revisit SalivaDirect as a testing option.
On October 27, an article published by the New Haven Independent indicated that Grubaugh proposed weekly testing with SalivaDirect for every high school student, faculty and staff member of New Haven Public Schools. The proposal, according to the article, was well-received by Board of Education members and also left open the possibility of testing younger students at different schools as well.
“If Yale Health had the capacity and resources to offer SalivaDirect it could help improve test turnaround time as well as provide the opportunity to support other local groups,” Wyllie wrote in an email to the News.
According to Wilson, Yale Health has roughly 45,000 members, which includes students, as well as 80 percent of Yale employees and their families.
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