Figure 3.

Three groups of serum total and IgG SARS-CoV-2 spike antibody responses were observed by SARS-CoV-2: (1) low, (2) intermediate, and (3) high. The cutoff points for the low group total ab level ranged from 0 to 600 μg/mL and, for the IgG level, from 0 to 5μg/mL; the cutoff points for the intermediate group total ab level ranged from 601 to 2000 μg/mL and for the IgG from 5 to 17 μg/mL; the cutoff points for the high group total ab level ranged from 2001 to >2500 μg/mL and, for the IgG level, from 17.1 to >20 μg/mL. IgG = Immunoglobulin G; SARS-CoV-2 = severe acute respiratory syndrome coronavirus 2; ab = antibody. Reproduced with permission from Ref. 14.