TABLE 3.
Performance characteristics of four commercially available anti-SARS-CoV-2 IgG assays
| Assay | % Sensitivity (no. of serum samples) |
% Specificity (no. of serum samples) |
||||||
|---|---|---|---|---|---|---|---|---|
| Inpatients, days post-symptom onseta
|
Outpatients, days post-first RT-PCR positive resultb
|
Healthy donors | Cross-reactivity panel | Overall (95% CI) | ||||
| ≤7 | 8–14 | ≥15 | ≤7 | ≥20 | ||||
| Abbott | 10.5% (4/38) | 49.5% (45/91) | 91.8% (56/61) | 18.2% (2/11) | 95.7% (22/23) | 100% (149/149) | 99% (104/105) | 99.6% (97.6%–100%) |
| Epitope | 2.6% (1/38) | 45.1% (41/91) | 100% (61/61) | 9.1% (1/11) | 56.5% (13/23) | 100% (149/149) | 99% (104/105) | 99.6% (97.6%–100%)c |
| Euroimmun | 0% (0/38) | 27.5% (25/91) | 100% (61/61) | 18.2% (2/11) | 91.3% (21/23) | 99.3% (148/149) | 96.2% (101/105) | 98% (95.3%–99.3%)d |
| Ortho-Clinical | 2.6% (1/38) | 38.5% (35/91) | 100% (61/61) | 9.1% (1/11) | 95.7% (22/23) | 99.3% (148/149) | 100% (105/105) | 99.6% (97.6%–100%) |
a
The number of unique patients providing samples collected ≤7, 8–14, and ≥15 days post-symptom onset was 11, 28, and 14, respectively.
b
The number of unique patients providing samples collected ≤7 and ≥15 days post-first positive RT-PCR result was 11 and 23, respectively.
c
Overall specificity is 98% (95% CI, 95.3%–99.3%) if indeterminate results are counted as positive.
d
Overall specificity is 97.2% (95% CI, 94.3%–98.8%) if indeterminate results are counted as positive.