It’s the latest example of how the ongoing SARS-CoV-2 pandemic is making it possible for new competitors to enter the clinical laboratory marketplace

In response to increasing demand for COVID-19 testing, warehouse retailer Costco (NASDAQ:COST) is seizing the opportunity to sell at-home saliva self-collection test kits to its customers. It makes Costco the latest company to enter the market for SARS-CoV-2 testing and compete against clinical laboratories.

And these non-invasive tests—which are as simple as spitting saliva into a container and mailing it to a medical laboratory—may be more effective at detecting the SARS-CoV-2 coronavirus than uncomfortable nasal swabs. 

Costco is selling its COVID-19 Saliva PCR Test Kit for $129.99 ($139.99 with video observation). Included in the price is a self-collection device, a biohazard bag, a sticker for personal data, and a box for shipping the saliva to a medical laboratory.

The test is actually P23 Labs’ TaqPath SARS-CoV-2 assay and will be administered by Azova, a digital health services provider. P23 says their test has a 98% sensitivity and 99% specificity, according to Business Insider.

The Costco P23 test kit above, “uses parts from Thermo Fisher Scientific and works with collection kits made by testing companies Everlywell and OraSure Technologies, according to the FDA and a P23 spokesperson,” Business Insider reported. “Samples are tested in [P23’s] lab in Little Rock, Arkansas.” (Photo copyright: Costco.)

Saliva-Collection Kits Gain Popularity and FDA Emergency Use Authorizations

P23 Labs’ assay is one of 12 COVID-19 home tests that have received US Food and Drug Administration (FDA) Emergency Use Authorization (EUA). Three of which use saliva specimens.

The FDA’s EUA authorization summary for the P23 assay states it is “for use with saliva specimens that are self-collected at home or in a healthcare setting with or without the supervision and/or assistance of [a healthcare provider (HCP)], by individuals using the P23 At-Home COVID-19 Test Collection Kit, when determined to be appropriate by an HCP based on the results of a COVID-19 medical questionnaire. This test is also for use with nasal swab specimens that are self-collected at home or in a healthcare setting with or without the supervision and/or assistance of an HCP by individuals.”

In a news release announcing the first diagnostic test using saliva specimens, oncologist and FDA Commissioner Stephen Hahn, MD, said that “Authorizing additional diagnostic tests with the option of at-home sample collection will continue to increase patient access to testing for COVID-19. This (saliva sample collection) provides an additional option for the easy, safe, and convenient collection of samples required for testing without traveling to a doctor’s office, hospital, or testing site.” That test was manufactured by Clinical Genomics laboratory of Rutgers New Jersey Medical School.

Below is a list from Business Insider for at-home self-collection SARS-CoV-2 coronavirus tests that have received an FDA EUA. Most can be ordered online, and prices range from $109 to $149, which may be covered by insurance depending on the health plan.

Saliva coronavirus home tests:

Nasal swab coronavirus home tests:

Yale Study Indicates Saliva Tests Have Greater Detection Sensitivity over Swab

Should consumers choose COVID-19 saliva tests over nasal cavity swab tests? Maybe.

A study led by the Yale School of Public Health found and “conducted at Yale New Haven Hospital with 44 inpatients and 98 health care workers—found that saliva samples taken from just inside the mouth provided greater detection sensitivity and consistency throughout the course of an infection than the broadly recommended nasopharyngeal (NP) approach. The study also concluded that there was less variability in results with the self-sample collection of saliva,” states a Yale University news release.

In, “Saliva Is More Sensitive for SARS-CoV-2 Detection in COVID-19 Patients than Nasopharyngeal Swabs,” published on the preprint server medRxiv, Yale researchers also noted a saliva test—as compared to a test using a nasal swab—is less invasive and more likely to be reliably self-administered. However, they remain cautious about jumping to saliva as a specimen versus nasal swabs.

Anne Wyllie, PhD, Associate Research Scientist at Yale School of Public Health, told Time magazine, “Saliva itself is a newer diagnostic method, and a lot of people don’t know how to work with it, are scared to work with it, or not sure how to work with it. Just because a protocol is working with swabs doesn’t mean the same protocol will work with saliva.” Nevertheless, public demand for less invasive COVID-19 testing means clinical laboratories may soon be receiving more requests for processing saliva over nasal swabs. (Photo copyright: Yale University.)

Yale received FDA EUA for SalivaDirect, a real-time quantitative polymerase chain reaction (RT-qPCR) for detection of SARS-CoV-2. However, SalivaDirect is not an “at-home” test. It requires saliva samples to be self-collected into a sterile container in the presence of a healthcare professional, and is being provided by Yale to clinical laboratories as an “open source” protocol, the FDA said in a news release.

“We are trying to work with smaller local labs that want to get up and running to support schools, community groups, universities, and colleges,” Wyllie told Time.

In “Saliva or Nasopharyngeal Swab Specimens for Detection of SARS-CoV-2,” published in the New England Journal of Medicine (NEJM), Wyllie and others suggest saliva can be just as effective in detecting the coronavirus that causes COVID-19. In their study, COVID-19 patients who were tested by healthcare workers using nasopharyngeal swabs were then asked to collect their own saliva samples.

The researchers found that “Collection of saliva samples by patients themselves negates the need for direct interaction between healthcare workers and patients. This interaction is a source of major testing bottlenecks and presents a risk of nosocomial infection. Collection of saliva samples by patients themselves also alleviates demands for supplies of swabs and personal protective equipment. Given the growing need for testing, our findings provide support for the potential of saliva specimens in the diagnosis of SARS-CoV-2 infection.”

The Yale scientists used primer sequences identified by the Centers for Disease Control and Prevention to detect the coronavirus. They found more SARS-CoV-2 RNA in saliva specimens than in the nasopharyngeal swab specimens. Also, 81% of saliva samples were positive one to five days after diagnosis, as compared to 71% of the nasopharyngeal swab specimens. 

“The findings suggest saliva specimens and nasopharyngeal swab specimens have at least similar sensitivity in the detection of SARS-CoV-2 during the course of hospitalization,” the researchers wrote in their NEJM paper.

The increasing popularity of at-home COVID-19 testing—along with studies showing that results improve when specimens are self-collected—suggest that medical laboratory managers should closely monitor the rise of COVID-19 home tests, as well as progress being made in saliva for diagnosing the SARS-CoV-2 coronavirus.

Further, it might be a smart strategy for clinical laboratories with the capability to perform this testing to approach retailers in their region and establish relationships where retailers sell the collection kits, and the lab performs the test and reports the results.

Since patients pay cash for the SARS-CoV-2 tests at the time they purchase the kits, clinical labs are guaranteed payment for the tests without the need to submit claims to consumers’ insurance companies. That’s another benefit to these types of arrangements.

—Donna Marie Pocius

Related Information:

Costco Sells At-Home COVID-19 Tests Using Saliva Samples

EUA for the P23 Labs TaqPath SARS-CoV—2 Assay

FDA Authorizes First Diagnostics Test Using Home Collection Saliva

There are 12 Coronavirus Tests You Can from Home: How They Work and How to Get One

Saliva Samples Preferable to Deep Nasal Swabs Testing for COVID-19

Saliva is More Sensitive for SARS-CoV-2 Detection in COVID-19 Patients Than Nasopharyngeal Swabs

FDA Issues Emergency Use Authorization Yale School of Public Health

COVID-19 Saliva Spit Test

Saliva or Nasopharyngeal Swab Specimens for Detection of SARS-CoV-2