Clinical performance evaluation of a SARS-CoV-2 Rapid Antibody Test for determining past exposure to SARS-CoV-2

OBJECTIVES: Due to the number of asymptomatic infections and limited access to high-performance antibody tests, the true prevalence and seropositivity of SARS-CoV-2 infection remains unknown. To fill this gap, the clinical performance of a point-of-care SARS-CoV-2 Rapid Antibody Assay, a chromatographic immunoassay for detecting IgM/IgG antibodies, in near patient settings was assessed. METHODS: Forty-two anti-SARS-Cov-2 positive (CoV+) and 92 anti-SARS-Cov-2 negative (CoV–) leftover samples from before December 2019 were assessed; the Elecsys® Anti-SARS-CoV-2 was used as the reference assay. Analytical specificity was tested using leftover samples collected before December 2019 from patients with common cold symptoms. RESULTS: The SARS-CoV-2 Rapid Antibody Test was 100.0% (95% CI 91.59–100.0) sensitive and 96.74% (95% CI 90.77–99.32) specific, with 0.00% assay failure rate. No cross-reactivity was observed against the common cold panel. Method comparison was additionally conducted by two external laboratories, using 100 CoV+ and 275 CoV– samples, also comparing whole blood versus plasma matrix. The comparison demonstrated 96.00% positive and 96.36% negative percent agreement for plasma with the Elecsys Anti-SARS-CoV-2 and 99.20% percent overall agreement between whole blood and EDTA plasma. CONCLUSION: The SARS-CoV-2 Rapid Antibody Test demonstrated similar performance to the manufacturer’s data and a centralised automated immunoassay, with no cross-reactivity with common cold panels.