Figure 1.

SARS-CoV-2 IgM, IgA, and IgG Responses of Recovered COVID-19 Patients

(A–C) Plasma ELISA titers to SARS-CoV-2 spike RBD. (A) IgG. (B) IgM. (C) IgA. Neg, unexposed donors from 2015–2018 (n = 20); COVID, convalescing COVID-19 patients (n = 20). All data are shown as ELISA titers based on a standard. The dotted line indicates limit of detection. Geometric mean titers with geometric SDs are indicated.

(D–I) Immunophenotyping of mononuclear leukocytes. Frequency of (D) CD3⁺ total T cells, (E) CD4⁺ T cells (CD4⁺CD3⁺), (F) CD8⁺ T cells (CD8⁺CD3⁺), (G) CD19⁺ B cells (CD19⁺CD3^–), (H) CD3^–CD19^– cells, and (I) CD14⁺CD16^– monocytes (CD3^–CD19^–CD56^–) from the PBMCs of unexposed donors (Neg, n = 13) or convalescing COVID-19 patients (COVID, n = 14). Data were analyzed using the Mann-Whitney test with mean and standard deviation shown.

^∗p < 0.05, ^∗∗∗∗p < 0.0001. See also Figures S1 and S2.