Stability of SARS-CoV-2 RNA in Nonsupplemented Saliva

D espite increased diagnostic testing capacity for severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), testing in many countries, including the United States, is still inadequate for slowing the coronavirus disease (COVID-19) pandemic.Many persons still do not have access to SARS-CoV-2 testing, and for some that do, an imbalance between supply and demand at large testing centers leads to long delays before results are received.The demand for testing will only increase as many schools, colleges, and workplaces reopen.Ideally, specialized population surveillance-oriented testing would require minimal diversion of resources from clinical diagnostic testing, be affordable and scalable, and enable rapid and reliable virus identifi cation for persons with asymptomatic or subclinical infections.Thus, simplifying the sample collection and testing workfl ow is critical.A simple solution is saliva collection.Saliva is a sensitive source for SARS-CoV-2 detection (1-3) and an alternative sample type for antigen and antibody testing (4,5).In addition, saliva collection is noninvasive, can be reliably performed without trained health professionals, and does not rely on a sometimes-limited swab supply.However, almost all saliva-based tests approved by the US Food and Drug Administration require specialized collection tubes containing stabilization or inactivation buffers that are costly and not always available.Moreover, as saliva continues to gain popularity as a potential specimen to aid testing demands, standardized collection methods have not been defi ned for saliva collection as they have for swab-based specimen collection.When true saliva is not collected (e.g., if it contains sputum), which can happen with COVID-19 inpatients when saliva is diffi cult to produce, specimens can be diffi cult to pipette (6).Combined with untested concerns regarding SARS-CoV-2 RNA stability in saliva, using supplements to reduce degradation and improve sample processing has become common.Previous work with saliva samples, however, has indicated that some buffers optimized for host nucleic acid stabilization may actually inhibit viral RNA detection (7) (S.B.