Table 1.
Characteristics of the sera used in the preliminary and the extended evaluations.
| Sera | Positive | Negative |
| Preliminary Evaluation | ||
| COVID-19 d0-7 | 19 | |
| COVID-19 d8-14 | 38 | |
| COVID-19 d>15 | 40 | |
| Hcov | 16 | |
| Lupus | 11 | |
| undefined | 56 | |
| Total = 180 | 97 | 83 |
| Extended Evaluation | ||
| COVID-19 d0-7 | 3 | |
| B19 | 13 | |
| CMV | 33 | |
| EBV | 22 | |
| FSME | 13 | |
| HSV1 | 14 | |
| HSV1-2 | 3 | |
| HSV2 | 4 | |
| Influ A | 27 | |
| Influ A/B | 1 | |
| Influ A/RSV | 2 | |
| Influ B | 9 | |
| Influ B/RSV | 1 | |
| Measles | 12 | |
| Measles-Mumps | 3 | |
| Mumps | 11 | |
| RSV | 15 | |
| Rubella | 17 | |
| undefined | 6 | |
| Varicella | 11 | |
| Total = 400 | 100 | 300 |
Positive sera: The categories d0-7, d8-14, >15d represent SARS-CoV-2 RT-PCR positive patients with expected-positive serum samples at different days post-symptoms onset. All Negative sera were sampled before November 1, 2019, anterior to the SARS-CoV-2 pandemic. Possible cross-reactions were investigated with sera positive for other known viruses. Undefined represent negative sera without association to other microorganism. Human coronaviruses (Hcov, 4x E229, 2x NL63, 6x OC43, 4x HKU1), Parvovirus (B19), Cytomegalovirus (CMV), Epstein-Barr virus (EBV), Tick-borne encephalitis virus (FSME), Herpes simplex virus 1 and 2 (HSV-1 and 2), Influenza A and B (Influ A and B), Respiratory Syncytial Virus (RSV), Measles virus, Mumps virus, Rubella, Varicella-zoster virus. Sera of patients with lupus were also included.