Dugas M, Grote-Westrick T, Vollenberg R, et al. - Since a very heterogeneous clinical course of COVID-19 infection is seen, with most cases managed in an outpatient setting, but a substantial proportion requiring intensive care, resulting in a high rate of fatalities, researchers hare conducted a biomarker study examining if and how prior infections with seasonal coronaviruses correlate with COVID-19 severity. Among 60 included patients with confirmed COVID-19 infections, patients with critical disease were identified having significantly lower levels of anti-HCoV OC43-NP and HCoV HKU1-NP antibodies at the first encounter compared with other COVID-19 patients. Per these results, prior infections with seasonal coronaviruses are possibly protective against a severe course of disease.