The COVID-19 pandemic has to date caused >7 million infections resulting in over 400,000 deaths. Following infection with SARS-CoV2, COVID-19 patients can experience mild or even asymptomatic disease, or can present with severe disease requiring hospitalization and mechanical ventilation. The case fatality rate can be as high as ~10% (1). Some severe COVID-19 patients display an acute respiratory distress syndrome (ARDS), reflecting severe respiratory damage. In acute respiratory viral infections, pathology can be mediated by the virus directly, by an overaggressive immune response, or both (2–4). However, in severe COVID-19 disease, the characteristics of, and role for the immune response, as well as how these responses relate to clinical disease features, remain poorly understood.