Saliva COVID-19 Tests Offer Way Around Nasopharyngeal Swab Shortage Bottlenecks

Shortages of the nasopharyngeal swabs used to collect respiratory samples for reverse transcription polymerase chain reaction (RT-PCR) tests has impeded the efforts of laboratories to meet the unprecedented demands for COVID-19 testing. So, the August 15 announcement that a saliva-based from the Yale School of Public Health has received emergency use authorization (EUA) from the U.S. Food and Drug Administration (FDA) is welcome news.

The Yale SalivaDirect test uses a new sample processing method allowing for collection of saliva samples in a sterile container, eliminating the need for nasopharyngeal swabs. The method also cuts out the separate nucleic acid extraction step, for which kits have also been in short supply. SalivaDirect allows for dualplex RT-qPCR method testing of low volumes of saliva treated with proteinase K followed by a heat inactivation. While the EUA allows for laboratories designated by the Yale School of Public Health, Yale will provide the SalivaDirect protocol freely to interested laboratories. “Providing this type of flexibility for processing saliva samples to test for COVID-19 infection is groundbreaking in terms of efficiency and avoiding shortages of crucial test components like reagents,” noted FDA Commissioner Stephen Hahn in a statement.

SalivaDirect is the fifth saliva test for SARS-CoV-2 to receive EUA from the FDA. The others are produced by (in order of EUA issuance):

• Rutgers Clinical Genomics Laboratory, with the original April EUA expanded in May to allow for at-home collection;
• Phosphorous Diagnostics;
• P23 Labs; and
• Clinical Reference Laboratory.

Here are other key new FDA EUAs and clearances announced in August:

New FDA Emergency Use Authorizations (EUAs) & Approvals