To et al. assessed the serial viral load, antibody kinetics, and viral genome of 23 patients with COVID-19 in Hong Kong and the authors suggest that posterior oropharyngeal (deep throat) saliva samples are a non-invasive and acceptable specimen that allow for healthcare workers to avoid the close contact with patients required during nasopharyngeal and throat swabbing. The authors found that salivary viral load was highest during the first week after symptom onset, the median viral load at presentation was 5·2 log copies per mL, older age was correlated with a higher viral load, and SARS-CoV-2 RNA could be detected for 20 days or longer in a third of the patients who survived. High viral load at presentation may explain why SARS-CoV-2 is transmitted easily from person-to-person and suggests the importance of strict infection control and early use of antiviral agents for high-risk persons.