Evaluation of three commercial and two non-commercial immunoassays for the detection of prior infection to SARS-CoV-2

Abstract

Abstract Background Serological testing provides a record of prior infection with SARS-CoV-2, but assay performance requires independent assessment. Methods We evaluated three commercial (Roche Diagnostics pan-IG, Epitope Diagnostics IgM and IgG) and two non-commercial (Simoa, Ragon/MGH IgG) immunoassays against 1083 unique samples that included 251 PCR positive and 832 pre-pandemic samples. Results The Roche assay registered the highest specificity 99.6% (3/832 false positives), the Ragon/MGH assay 99.5% (4/832), the primary Simoa assay model 99.0% (8/832), and the Epitope IgG and IgM 99.0 (8/830) and 99.5% (4/830) respectively. Overall sensitivities for the Simoa, Roche pan-IG, Epitope IgG, Ragon/MGH IgG, and Epitope IgM were 92.0%, 82.9%, 82.5%, 64.5% and 47.0% respectively. The Simoa immunoassay demonstrated the highest sensitivity among samples stratified by days post symptom onset (PSO), < 8\u2009days PSO (57.69%) 8-14\u2009days PSO (93.51%), 15-21\u2009days PSO (100%), and > 21\u2009days PSO (95.18%). Conclusions All assays demonstrated high to very high specificities while sensitivities were variable across assays.