LAUSR

Are interferon-mediated antiviral immune responses beneficial or detrimental in COVID-19? The severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) outbreak quickly developed into a pandemic in March 2020. To date, no vaccines or antiviral medications are available, and given the urgency, many clinical trials have started screening existing antiviral drugs for efficacy against SARS-CoV-2 infection. Among a variety of therapeutic approaches, the use of different types of interferon (IFN) as antiviral agents is under investigation owing to promising outcomes in other coronavirus-induced pathologies (1). Through different mechanisms and effector proteins, IFNs play an important role in the inhibition of viral replication (2). On pages 712 and 706 of this issue, Major et al. (3) and Broggi et al. (4), respectively, describe the mechanisms by which IFN-λ responses contribute to pathogenesis in viral pneumonias. Conversely, on page ZZZ, Hadjadj et al. (5) studied peripheral blood responses from a cohort of 50 patients with coronavirus disease 2019 (COVID-19), demonstrating that critically ill patients have reduced IFN responses paired with a proinflammatory response.