Fig. 4.

Serum levels of anti-SARS-CoV-2 IgG and IgM antibodies. A IgG levels in four patient groups: moderately-ill patients aged < 65 years (light blue), severely-ill patients aged < 65 years (blue), moderately-ill patients aged ≥65 years (light red), and severely-ill patients aged ≥65 years (red). IgG data was collected across all timepoints. B Polynomial regression of IgG was applied to fit the dynamic patterns of IgG from symptom onset to clinical outcomes (hospital discharge or death). C IgM levels in four patient groups. D Polynomial regression of IgM dynamics from symptom onset to clinical outcomes