COVID-19 Saliva Test as Effective as NPS Test

A recent study from South Korea showed that the less-invasive saliva test for COVID-19 gives just as accurate results as those of the nasopharyngeal specimen.

Published on February 15, 2021, a research team at the Department of Laboratory Medicine at Kangwon National University School of Medicine, led by Professor In-bum Suh, carried out the PCR test for COVID-19 on 90 hospitalized individuals with suspected COVID-19, both with saliva and nasopharyngeal methods.

As a result, both 'Allplex™ SARS-CoV-2 Assay' and 'Allplex™ SARS-CoV-2/FluA/FluB/RSV Assay' proved the saliva and nasopharyngeal test's percentage agreement for detecting COVID-19 was over 98.8%.

The research team also conducted a separate study on the extraction-free application, one without the nucleic acid extraction step, and found the percentage agreement between Seegene's extraction-free saliva test and extraction-free nasopharyngeal swab test to be over 96%.

In other words, the extraction-free method using saliva sampling would be just as applicable for the PCR test in detecting SARS-CoV-2.

Professor Suh stated in a press release, "the study has "clearly proven that saliva tests are just as accurate and effective as nasopharyngeal tests in precisely diagnosing COVID-19."

Generally, in COVID-19 PCR tests, the nucleic acid extraction process is considered a prerequisite to isolate and purify nucleic acid from specimens. Depending on the circumstances, however, some countries may not be fully equipped to carry out the extraction process. Despite a surge in testing capacity, some even face reagent shortages, eventually leading many laboratories to resort to an extraction-free method, concluded this study.