Table 1.
Characteristics and performance claimed by manufacturer of each assays.
| VNT | sVNT | ||||
|---|---|---|---|---|---|
| YHLO Biotechnologies | TECO Medical Group | Dynamiker Biotechnology | bioMérieux | ||
| PRNT50 | iFlash | TECO | Dynamiker | Vidas | |
| SARS-CoV-2 detected Ab | Total Ab | IgG | IgG | IgG | IgG |
| Assay type | Neutralization in cell culture | CLIA | ELISA | Immuno-chromatography | ELFA |
| Antigen | N/A | RBD | RBD | RBD | RBD |
| Positive threshold | 20 or 80 | AU/mL = 10 | UI/mL = 20 | NA | Index = 1 |
| Manufacturer sensitivity, % [95%CI] | N/A | 90 | 99.03 [94.07; 99.83] |
95.74 [85.75; 98.83] |
96.6 [82.2; 99.9] |
| Manufacturer specificity (% [95%CI]) | N/A | 98 | 100 [96.68; 100] |
99.15 [95.36; 99.85] |
99.9 [99.4; 100] |
Positivity was established according to manufacturers’ instructions. Sensitivity and specificity data were those described in the instruction for utilization sheet from each manufacturer. Specificity given by manufacturers was obtained from pre pandemic samples.
Abbreviations: Ab: antibodies, Ig: immunoglobulin, ELISA: enzyme-linked immunosorbent assay, CLIA: chemiluminescence immunoassay, ELFA: enzyme-linked fluorescent assay, RBD: receptor binding domain, CI: confidence interval, AU: arbitrary unit, UI: unit international.