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 …

Background A wide array of assays to detect the serologic response to SARS-CoV-2 have
been developed since the emergence of the pandemic. The majority of these are either
qualitative or semi-quantitative, detect antibodies against one antigenic target, and are not
adaptable to new antigens. Methods We developed a new, multiplex immunoassay to detect
antibodies against the receptor binding domain, S1 and S2 spike subunits and nucleocapsid
(N) antigens of SARS-CoV-2 (the CEPHR SARS-CoV-2 Serology Assay). This assay uses …