Table 2.

Strengths and weakness of NPS and saliva specimens

Specimen	Strengths	Limitations
NPS	Already established as the specimen of choice for the diagnosis of many viral respiratory infections [4, 5] Likely to be less variation in the sensitivity of the specimen if food/drink etc. is consumed before sample is taken Antigen tests are established for using NPS as their input	Uncomfortable and invasive specimen to collect Not suitable for children Requires trained HCWs in order for the sample to be collected Puts HCWs at risk of nosocomial infection Incorrect swabbing due to poor technique from administrator or resistance from the patient can impact sensitivity Not suitable for mass-testing/surveillance due to logistics and repeated sampling can cause adverse effects to the patient [13]
Saliva	Less invasive specimen to collect and therefore patients are more likely to get tested and give repeated samples Can be self-administered from home, so no trained HCWs or test sites are required Suitable for COVID-19 mass testing/ surveillance	No established collection, transport and processing protocol Time of day of sampling as well as food/drink/oral hygiene/smoking can impact the specimen’s sensitivity Antigen tests are not established for using saliva as their input