Performance and validation of an adaptable multiplex assay for detection of serologic response to SARS-CoV-2 infection or vaccination
Grace Kenny, Riya Negi, Sophie O’Reilly, A. Léon, Dana Alalwan, Colette Marie Gaillard, Gurvin Saini, Rosana Inzitari, Eoin R. Feeney, Obada Yousif, Aoife G. Cotter, Eoghan de Barra, Corinna Sadlier, Fiona Crispie, Peter Doran, Virginie Gautier, Patrick Mallon
Abstract
Measurement of quantitative antibody responses are increasingly important in evaluating the immune response to infection and vaccination. In this study we describe the validation of a quantitative, multiplex serologic assay utilising an electrochemiluminescence platform, which measures IgG against the receptor binding domain (RBD), spike S1 and S2 subunits and nucleocapsid antigens of SARS-CoV-2. The assay displayed a sensitivity ranging from 73 to 91% and specificity from 90 to 96% in detecting previous infection with SARS-CoV-2 depending on antigenic target and time since infection, and this assay highly correlated with commercially available assays. The within-plate coefficient of variation ranged from 3.8-3.9% and the inter-plate coefficient of variation from 11 to 13% for each antigen.