Clinical Performance Evaluation of a SARS-CoV-2 Rapid Antibody Test for Determining Past Exposure to SARS-CoV-2 (preprint)

ABSTRACT

The true prevalence and population seropositivity of SARS-CoV-2 infection remains unknown, due to the number of asymptomatic infections and limited access to high-performance antibody tests. To control the COVID-19 pandemic it is crucial to understand the true seroprevalence, but not every region has access to extensive centralized PCR and serology testing. Currently available rapid antibody tests lack the accuracy needed for recommendation by health authorities. To fill this gap, we analyzed and validated the clinical performance of a new point-of-care SARS-CoV-2 Rapid Antibody Assay, a chromatographic immunoassay for qualitative detection of IgM/IgG antibodies for use in near-patient settings. Analysis was performed using 42 Anti-SARS-Cov-2 positive (CoV+) and 92 Anti-SARS-Covid-2 negative (CoV-) leftover samples from before December 2019, using the Elecsys(R) Anti-SARS-CoV-2 as the reference assay. Analytical specificity was tested using leftover samples from individuals with symptoms of common cold collected before December 2019. The SARS-CoV-2 Rapid Antibody Test was 100.0% (95% CI 91.59-100.00) sensitive and 96.74% (95% CI 90.77-99.32) specific with an assay failure rate of 0.00%. No cross-reactivity was observed against the common cold panel. Method comparison was additionally conducted by two external laboratories, using 100 CoV+/275 CoV-samples, also comparing whole blood versus plasma matrix. The comparison demonstrated for plasma 96.00% positive/96.36% negative percent agreement with the Elecsys Anti-SARS-CoV-2 and overall 99.20% percent agreement between whole blood and EDTA plasma. The SARS-CoV-2 Rapid Antibody Test demonstrated similar clinical performance to the manufacturer's data and to a centralized automated immunoassay, with no cross-reactivity to common cold panels.