The difference between nasopharyngeal PCR and Saliva PCR lies in the type of sample and how the sample is taken.
Saliva sampling is much less invasive and painless, making it possible to collect saliva simply by placing saliva in a vial or tube.
By being less obtrusive, people are more willing to get tested repeatedly.
No trained personnel are required to take samples.
Fewer protective measures are required because the possibility of contagion during the samples collection.
The use of saliva samples saves waiting time for sample collection and therefore speeds up the availability of results.
Saliva samples are very stable even at room temperature, which simplifies transport.