| Specificity, % (95% CI) | Sensitivity, % (95% CI) | PPV, % (95% CI) | NPV, % (95% CI) | |
|---|---|---|---|---|
| RBD IgG | 87 (62–98) | 100 (89–100) | 100 (77–100) | 94 (80–99) |
| RBD IgM | 73 (48–89) | 97 (83–100) | 92 (65–100) | 88 (73–95) |
| Spike IgG | 67 (42–85) | 97 (83–100) | 91 (62–100) | 85 (70–94) |
| Spike IgM | 60 (36–80) | 97 (83–100) | 90 (60–100) | 83 (67–92) |
| Spike IgG1 | 71 (45–88) | 100 (87–100) | 100 (72–100) | 88 (73–95) |
| Spike IgG3 | 93 (70–100) | 97 (83–100) | 93 (70–100) | 97 (83–100) |
| Spike IgA | 67 (42–85) | 100 (89–100) | 100 (72–100) | 86 (71–94) |
| NP IgG | 93 (70–100) | 97 (83–100) | 93 (70–100) | 97 (83–100) |
Abbreviations: CI, confidence interval; ELISA, enzyme-linked immunosorbent assay; IgA, immunoglobulin A; IgG, immunoglobulin G; IgM, immunoglobulin M; NP, nucleocapsid protein; NPV, negative predictive value; PPV, positive predictive value; RBD, receptor binding domain.