Buitrago-Garcia D, Egli-Gany D, Counotte MJ, et al. - Via performing a living systematic review, a systematic review that provides an online summary of findings and is updated when relevant new evidence becomes available, researchers sought to address three questions: (1) Among people who become infected with SARS-CoV-2, what proportion remain asymptomatic during their infection course? (2) Among people with SARS-CoV-2 infection who are asymptomatic when diagnosed, what proportion had symptom development later during the disease course? (3) What proportion of SARS-CoV-2 transmission is accounted for by people who are either asymptomatic throughout infection or presymptomatic? They identified a total of 94 studies for inclusion. Overall, 20% of people with SARS-CoV-2 infection were estimated to remain asymptomatic during follow-up in 79 studies addressing this review question, however, biases in study designs limit the certainty of this measure. Thirty-one percent were estimated to remain asymptomatic in seven studies of defined populations screened for SARS-CoV-2 and then followed. Some evidence was gained suggesting the less likelihood of SARS-CoV-2 infection in contacts of people with asymptomatic infection vs in contacts of people with symptomatic infection. Findings thereby suggest that in most people who become infected with SARS-CoV-2, asymptomatic phase will not remain throughout the course of the infection. Given that presymptomatic and asymptomatic infections contribute to overall SARS-CoV-2 transmission, combination prevention measures, with enhanced hand hygiene, masks, testing tracing, and isolation strategies and social distancing, will continue to be needed.