Table 3.
Sensitivity (%) of SARS-CoV-2 N-, S1-, and RBD-Based Enzyme Immunoassays
| Sample | N | S1 | RBD | N + S1 | N + RBD |
|---|---|---|---|---|---|
| COVID-19 patients, acute phase (n = 92) | |||||
| IgG | 65.2 | 41.3 | 48.9 | 67.4 | 67.4 |
| IgA | 63.0 | 56.5 | 65.2 | 69.6 | 75.0 |
| IgM | 51.1 | 48.9 | 57.6 | 57.6 | 65.2 |
| IgG/IgA | 68.5 | 57.6 | 69.6 | 71.7 | 77.2 |
| IgG/IgM | 66.3 | 51.1 | 63.0 | 71.7 | 72.8 |
| IgA/IgM | 66.3 | 57.6 | 73.9 | 71.7 | 80.4 |
| COVID-19 patients, convalescent phase (n = 27) | |||||
| IgG | 96.3 | 85.2 | 85.2 | 96.3 | 96.3 |
| IgA | 81.5 | 92.6 | 96.3 | 96.3 | 100.0 |
| IgM | 55.6 | 74.1 | 88.9 | 81.5 | 88.9 |
| IgG/IgA | 96.3 | 96.3 | 100.0 | 100.0 | 100.0 |
| IgG/IgM | 96.3 | 85.2 | 92.6 | 96.3 | 96.3 |
| IgA/IgM | 81.5 | 96.3 | 100.0 | 96.3 | 100.0 |
Abbreviations: COVID-19, coronavirus disease 2019; Ig, immunoglobulin; N, nucleoprotein; RBD, receptor binding domain; S1, spike protein; SARS-CoV-2, severe acute respiratory syndrome coronavirus 2.