Thommes L, Burkert FR, Ottl KW, et al. - This study was sought to compare four SARS-CoV-2 antigen tests in hospitalized patients. Researchers examined parallel nasopharyngeal/oropharyngeal swabs in 87 consecutive patients who admitted to our department with moderate to severe COVID-19 by means of quantitative RT-PCR (Cobas, Roche) and up to four antigen tests from different distributors. The study demonstrated that most antigen tests had a sufficient sensitivity to identify symptomatic individuals infected with SARS-CoV-2 and with transmissible infection. During follow-up, the outcomes revealed antigen testing may not be suitable to distinguish loss of infectivity in COVID-19 individuals. Newly introduced antigen tests require to be confirmed in a clinical or primary care setting to characterize their clinical usefulness.