Ratio between IgG against the spike protein of seasonal coronaviruses and SARS- CoV-2 is associated with a fatal outcome of hospitalized COVID-19 patients

Abstract SARS-CoV-2 infection elicits a cross-reactive and back boosting immune response from prior exposure to any of the human seasonal coronaviruses (HCoVs), but is has yet to be determined whether this response is associated with fatal outcome of severe COVID-19 disease. In a cohort of 58 hospitalized patients, we have shown that heterologous immune responses are associated with increased disease severity. Here, we report that a lower anti-spike IgG ratio of SARS-CoV-2 to HCoVs, in particular to the human coronavirus 229E, correlates with decreased neutralizing antibody titers, and is associated with a fatal disease course. These results support the hypothesis that pre-existing humoral immunity to spike antigens of HCoVs may impair an efficient immune response during COVID-19.