Validation of a Self-administrable, Saliva-based RT-qPCR Test Detecting SARS-CoV-2

Background Rapid and easy COVID-19 diagnostic testing is essential to controlling the pandemic and facilitating safe resumption of clinical care, employment and other social activities. Methods This study was conducted to validate an self-administrable saliva-based RT-qPCR test for the SARS-CoV2 virus under controlled laboratory conditions (analytical validation) according to federal guidance. An additional clinical study assessed positive (n = 34) and negative (n = 57) nasopharyngeal swab samples collected contemporaneously with saliva samples. Assessments for analytical specificity, sensitivity, cross reactivity and sample stability to simulate shipping conditions were conducted. Results Positive and negative agreement with third-party laboratory results were reported as 97.1% and 96.5–98.2%, respectively. Limit of detection was established at 5 copies/µL. Stability through simulated shipping conditions found 100% concordance up to 56 hours after collection. Discussion: These data validate a self-collected saliva-based COVID-19 RT-qPCR assay that performs comparably well to an assay of health care-provider administered nasopharyngeal swab samples. Accordingly, the United States Food and Drug Administration granted emergency use authorization in June 2020. Use of the saliva-based assay overcomes barriers to the necessary widespread testing, including strained health care resources, supply chain disruptions of laboratory materials, testing and protective equipment and exposure risks due to close interpersonal contact.