At a population level, the humoral response to SARS-CoV-2 is heterogeneous. In the course of our development of EpitoGen SARS-CoV-2 assays we observed that significant numbers of samples were only reactive for either the Spike or Nucleocapsid antigen alone. Therefore, traditional antibody assays expressing either the Spike or Nucleocapsid antigen only are less than effective. Also, accumulation of SARS-CoV-2 mutations will further reduce sensitivity.
To overcome this, the Universal EpitoGen® COVID-19 ELISA test was designed for maximum sensitivity. Using EpitoGen technology, a set of 15 immunodominant epitopes from N, S, M, ORF3a and ORF7a viral proteins, and their corresponding major circulating mutants (45 prevalent mutations) were fused together to create a universal antigen. It is designed for the detection of IgG antibody response to SARS-CoV-2 infection and immunisation.
This is the first Epitope-based SARS-CoV-2 test, the only test to utilise five viral SARS-CoV-2 proteins in one assay, and to include prevalent mutations.
The epitopes selected are also IgM and IgA rich meaning the assay is suitable for the detection of IgA and IgM antibody responses to evaluate active SARS-CoV-2 infection or mucosal immunity.
The combinations of these composite-epitopes expressed as antigens in the assay offers the ability to detect broadest range of human SARS-CoV-2 antibodies.