Table 2.
Analytical methods used to measure SARS-CoV-2 antibody level
| Center | Period | Method | Mean | SD |
|---|---|---|---|---|
| Bologna | April 2020 – June 2020 | ELISA (IgG and IgM) | Q | - |
| July 2020- December 2020 | ECLIA (IgG+IgM anti-N) | Q | - | |
| Jan 2021- May 2021 | ECLIA-RBD (IgG anti-S) | 1339.04 | 938.27 | |
| Brescia | April 2020- July 2020 | ECLIA (IgG anti-S) | 7.31 | 20.19 |
| March 2021-April 2021 | ECLIA-RBD (Ig anti-S) | 2182.12 | 1836.41 | |
| Verona | May 2020 – Jan 2021 | CLIA (IgM and IgG) | 0.655 | 2.685 |
| Jan 2021 – May 2021 | TrimericS IgG assay | 1984.99 | 4865.50 |
Q, qualitative result