Evaluation of four laboratory-based SARS-CoV-2 IgG antibody immunoassays

OBJECTIVES: To evaluate the diagnostic performances of four SARS-CoV-2 IgG antibody immunoassays. METHODS: Following immunoassays were studied: Abbott's SARS-CoV-2 IgG assay, Diasorin's Liaison SARS-CoV-2 S2/S2 IgG assay, Euroimmun's Anti-SARS-CoV-2 IgG ELISA, and Roche's Elecsys Anti-SARS-CoV-2 assay. Specificity was retrospectively evaluated with 38 samples from 2019. Sensitivity samples (n = 147) were taken from SARS-CoV-2 real-time PCR-positive patients who developed COVID-19 symptoms ten days earlier. RESULTS: Mean specificity was 96.6%. Mean sensitivity was 62.7% from ten days after onset of symptoms, 84.4% from 15 days after onset of symptoms, and 87.5% from 20 days after onset of symptoms. CONCLUSIONS: Specificity was high, while Abbott and Roche were 100% specific. Sensitivity increased over time, with Abbott and Roche having the highest sensitivity at all time points with ≥90% from 20 days after symptoms' onset. These findings may assist in selecting SARS-CoV-2 IgG antibody immunoassays for additional diagnostics, epidemiological research, and vaccine development.