After six years, specific IgG Abs to SARS-CoV were undetectable in 21/23 (91.3%) of recovered patients

FIGURE 1. Dynamic changes in specific IgG Ab against SARS-CoV in patients who recovered from SARS. The geometric mean reciprocal titers (black line) are shown for the IgG Ab of the group of patients. The number of serum samples tested at each visit is given in the figure. The IgG titers of patient A (red line) and patient B (green line) are demonstrated.