Table 1 Commercial assays employed in the study to identify IgG anti-SARS-CoV-2.

LIAISON® SARS-CoV-2 S1/S2 IgG

DiaSorin

S1/S2

CLIA^a

Negative: <12.0 AU/mL

Equivocal: 12.0 ≤ x < 15.0 AU/mL

Positive: ≥15.0 AU/mL

Elecsys® Anti-SARS-CoV-2

Roche

N

ECLIA^b

Positive: <1.0

Negative: ≥1.0

ARCHITECT® SARS-CoV-2 IgG

Abbott

N

CMIA^c

Negative: <1.4

Positive: ≥1.4