"Living" systematic review captures and updates evidence on "long COVID" Researchers in the United Kingdom have set up a “living” systematic review in response to the rapidly emerging evidence-base for “long COVID” – the term used to refer to coronavirus disease 2019 (COVID-19) symptoms that persist for longer than would usually be expected. Some people who develop COVID-19 experience symptoms that persist for weeks or even months beyond the two to six weeks it typically takes for people to recover. These individuals sometimes develop medical complications that may have long-lasting health effects. However, “a precise case definition of long COVID is problematic because, currently, there is little consensus on the exact range, prevalence, and duration of symptoms in post-acute COVID-19,” says Charitini Stavropoulou from the University of London and colleagues.