Since January 2020 Elsevier has created a COVID-19 resource centre with free information in English and Mandarin on the novel coronavirus COVID19. The COVID-19 resource centre is hosted on Elsevier Connect, the company's public news and information website. Elsevier hereby grants permission to make all its COVID-19-related research that is available on the COVID-19 resource centre - including this research content - immediately available in PubMed Central and other publicly funded repositories, such as the WHO COVID database with rights for unrestricted research re-use and analyses in any form or by any means with acknowledgement of the original source. These permissions are granted for free by Elsevier for as long as the COVID-19 resource centre remains active.In a recent article in the Journal, Azzi and colleagues (1) evaluated saliva samples of 25 COVID-19 patients by real time RT-PCR. In this study, all individuals had severe or very severe infection. All of them had SARS CoV-2 detected in saliva samples and there is no information regarding the presence of liver diseases.