Table 2.
Immunoassays of SARS-CoV-2 antibodies used in the study.
| Manufacturer | Methodology | Antigen Used | Evaluation of the Results | Manufacturer’s Catalog Number |
||
|---|---|---|---|---|---|---|
| Negative | Gray Zone | Positive | ||||
| Abbott | CLIA | IgG NP | <1.4 | - | ≥1.4 | 6R86 |
| Diasorin | CLIA | IgG anti-S1/S2 | <12 | 12–15 | ≥15 | 311450 |
| Roche | CLIA | Total Ig NP | <1.0 | - | ≥1.0 | 09 203 095 190 |
| Beckman Coulter | CLIA | IgG anti-S1 RBD | <0.8 | 0.8–1.0 | ≥1.0 | C58961 |
| Euroimmun | ELISA | IgG anti-S1 | <0.8 | 0.8–1.1 | ≥1.1 | EI 2606-9601 G |
Legend: The individual assays report the results as follows: Abbott as an index value (S/C); Diasorin as arbitrary units per mililiter (AU/mL); Roche as cut-off index (COI); Beckman Coulter as an index value (S/CO); Euroimmun as a ratio (number only).