COVID-19, cytokines and immunosuppression: what can we learn from severe acute respiratory syndrome?

A severe outbreak of coronavirus disease 2019 (COVID-19) emerged in China in December 2019, and spread so rapidly that more than 200,000 cases have so far been reported worldwide; on January 30, 2020, the WHO declared it the sixth public health emergency of international concern. The two previously reported coronavirus epidemics (severe acute respiratory syndrome [SARS] and Middle East respiratory syndrome [MERS]) share similar pathogenetic, epidemiological and clinical features as COVID-19. As little is currently known about SARS-CoV-2, it is likely that lessons learned from these major epidemics can be applied to the new pandemic, including the use of novel immunosuppressive drugs