Rapid, Point-of–Care At-Home Collection Saliva Tests
Rapid, point-of-care tests use a mucus sample from the nose or throat, but can be analyzed at the doctor’s office or clinic where the sample is collected and results may be available in minutes.  These may be molecular or antigen tests. At-home collection tests, available only by prescription from a doctor, allow the patient to collect the sample at home and send it directly to the lab for analysis. Saliva tests allow a patient to spit into a tube rather than get their nose or throat swabbed.  Saliva tests may be more comfortable for some people and may be safer for health care workers who can be farther away during the sample collection.

Source:  Coronavirus Testing Basics, CDC, July 2020