A Comparison of the Performance of SARS-CoV-2 Antibody Assays in Healthcare Workers with COVID-19

Aims Since its emergence, significant interest surrounds the use of SARS-CoV-2 serological tests as an alternative or as an adjunct to molecular testing. However, given the speed of this pandemic, paralleled with the pressure to develop and provide serological tests in an expediated manner, not every assay has undergone the rigorous evaluation that is usually associated with medical diagnostic assays. We aimed to examine the performance of several commercially available SARS-CoV-2 IgG antibody assays among participants with confirmed COVID-19 disease and negative controls. Methods Serum taken between day 17 and day 40 post onset of symptoms from 41 healthcare workers with RT-PCR confirmed COVID-19 disease, and pre-pandemic serum from 20 negative controls, were tested for the presence of SARS-CoV-2 IgG using 7 different assays including point-of-care (POC) and laboratory-based assays. Results Assay performance varied. The lab-based Abbott diagnostics SARS-CoV-2 IgG assay proved to be the assay with the best positive and negative predictive value, and overall accuracy. The POC Nal von Minden GmbH and Biozek assays also performed well. Conclusion Our research demonstrates the variations in performance of several commercially available SARS-CoV-2 antibody assays. These findings identify the limitations of some serological tests for SARS-CoV-2. This information will help inform test selection and may have particular relevance to providers operating beyond accredited laboratories.