The new saliva-based test developed at Arizona State University (ASU) is just as good as nasopharyngeal (NP) swab tests. "This new saliva-based test will be a real game-changer for those individuals who want to know whether or not they have an active COVID-19 infection," said ASU Biodesign Institute Executive Director Joshua LaBaer, who leads the ASU COVID-19 research.

As restrictions end and businesses and schools reopen, early testing would be the best way to prevent the spread of novel coronavirus, he said.

Saliva based coronavirus test
Arizona State University Biodesign Institute researcher Joe Miceli gives a demo of the saliva sample collection procedure. ASU Biodesign Institute

Diagnostic tests detect the coronavirus infection by measuring the amount of virus present in the body. As it takes almost eight to nine days to develop COVID-19 symptoms, diagnostic tests have been proved to accurately detect an early infection, potential in spreading the pathogen.

A study from Yale School of Public Health showed that SARS-CoV-2 detection by saliva samples yielded greater detection sensitivity and consistency than the NP swab tests.

How it Works

This saliva diagnostic test works by getting the patient to spit saliva into a screw-top tube through a straw enabling easy collections at drive-thru sites, offices, the workplace, and home. In addition to maintaining an easy test kit supply chain, the new test would bring down the testing cost.

The saliva test uses the same diagnostic qPCR assay as the swab test and is 100 percent accurate. The present swab based testing is faced with a bottleneck of not being able to quickly obtain samples, LaBaer said. Even trained medical professionals collect an average of 100 nasopharyngeal (NP) swabs in a four-hour window of drive-thru testing. "The goal of the saliva tests was to overcome these obstacles," he added.

1,200 Tests Per Day

Covid test
Representational Image Pixabay

ASU's Biodesign Institute is piloting this saliva-based testing alongside nasal swab collections to validate and verify the new test, also to reconfigure its high-throughput robotic instruments, currently having the capacity to perform 1,200 diagnostic tests per day.

The results showed that the "saliva-based tests were just as good, if not even better, as those collected from NP swabs," LaBaer said. He pointed out that saliva tests have several benefits over the NP swab tests.

Saliva Tests are Safer

Research shows that saliva tests are just as sensitive as NP swabs for detecting SARS-CoV-2 infections along with offering safety as opposed to NP swabs that pose risk to health care workers as the collection process makes people sneeze or cough. Saliva tests are self-administered and need only minimum interaction.

Given the shortage of personal protective equipment (PPE) needed to administer swab tests, saliva test works better as this requires less PPE when obtaining samples, while also reducing staff involved in the process. The Biodesign Institute has applied for FDA Emergency Use Authorization (EUA) for the saliva-based test.