Research in Brief
Paul Bastard and colleagues screened for antibodies against type I interferons in 987 patients hospitalised with life-threatening COVID-19 pneumonia, as well as in 663 individuals with asymptomatic or mild SARS-CoV-2 infection and 1227 people unexposed to SARS-CoV-2 (samples collected before the pandemic). They found that 101 (10·2%) of 987 patients with life-threatening COVID-19 pneumonia had…