Understanding immune responses to severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) is crucial to contain the COVID-19 pandemic. Using a multiplex approach, serum IgG responses against the whole SARS-CoV-2 proteome and the nucleocapsid proteins of endemic human coronaviruses (HCoVs) were measured in SARS-CoV-2-infected donors and healthy controls. COVID-19 severity strongly correlated with IgG responses against the nucleocapsid (N) of SARS-CoV-2 and possibly with the number of viral antigens targeted. Furthermore, a strong correlation between COVID-19 severity and serum responses against N of endemic alpha- but not betacoronaviruses was detected. This correlation was neither caused by cross-reactivity of antibodies, nor by a general boosting effect of SARS-CoV-2 infection on pre-existing humoral immunity. These findings raise the prospect of a potential disease progression marker for COVID-19 severity that allows for early stratification of infected individuals.
Keywords: COVID-19; SARS-CoV-2; coronavirus; multiplex serology; nucleocapsid protein.
Copyright © 2022 Nückel, Planatscher, Mohr, Deichl, Mijočević, Feuerherd, Wolff, Erber, Schneider, Quante, Winter, Ruland, Hapfelmeier, Hammerschmidt, Moosmann, Protzer, Behrends and Mautner.