In the recent updates of “Interim Guidelines for Collecting and Handling of Clinical Specimens for COVID-19 Testing” on February 26, 2021, CDC includes saliva as one of the selected specimens for the test. This decision is based on solid scientific evidence.
In one meta-analysis study, scientists analyzed data from 37 studies, comprising 7,169 participants with 7,332 paired saliva samples and nasopharyngeal swabs. Analysis results shown sample collection through saliva or nasopharyngeal swabbing does not differ significantly in sensitivity. Another meta-analysis study from 16 studies including 5,900 participants shows that saliva-based tests have 83 percent accuracy, while nose-throat swab tests have 85 percent accuracy.