Generation of IgG antispike but not anti-NC antibodies is dependent on time after diagnosis. Levels of total IgG specific for trimeric spike, S1, RBD, S2, or NC epitopes. Serum is from (dark red) transplant recipients ≤14 days after diagnosis, (brown) transplant recipients >14 days after diagnosis, (dark blue) immunocompetent individuals ≤14 days after diagnosis, and (light blue) immunocompetent individuals >14 days after diagnosis. MFI, mean fluorescence intensity; ns, not significant. *P=0.05; **P=0.01; ***P<0.001.