Figure 2: Longitudinal SARS-CoV-2 antibody kinetics and estimated assay sensitivities by time and hospitalization status.

(Upper row) Time since symptom onset (offset by 21 days) is shown on the x-axis versus the log-transformed antibody response for each of the Abbott ARCHITECT, Roche Elecsys, and Ortho VITROS IgG assays, stratified by hospitalization status. For asymptomatic individuals, the time since the first positive PCR test (offset by 21 days) was used. This time-metric is referred to as ‘time since seroconversion’ hereafter. Longitudinal samples are connected by black lines. Black dotted lines indicate cutoff values for positivity on that assay. (Lower row) Estimated sensitivity of each assay (showing posterior median estimates as the solid line and 95% credible intervals), stratified by hospitalization status, from 0 to 365 days after seroconversion. The dashed vertical line in purple indicates the maximum observed time on the corresponding panel above (i.e., x=136 for non-hospitalized and x=118 for hospitalized).