ACE2 and COVID-19: With consideration of the antibody kinetics from days since enrollment until either death or 100 DPE among hospitalized COVID-19 patients, anti-S IgG, anti-S-RBD IgG, anti-N IgG, anti-S-RBD IgA, and ACE2 binding inhibition (Fig. 6a–e) were maintained at higher levels over time among deceased patients as compared to other hospitalized patients.