A powerful trio of CE-marked tests from EUROIMMUN enables comprehensive investigation of immune responses to SARS-CoV-2 following COVID-19 vaccination or infection. The analyses encompass quantitative measurement of anti-S1/RBD antibodies, detection of neutralising antibodies targeting S1/RBD and analysis of specific T cells.
Antibody detection
Quantitative detection of antibodies against S1/RBD aids assessment of the immune reaction following vaccination with spike protein-based vaccines or the individual immune response to SARS-CoV-2 after infection. The fully automatable Anti-SARS-CoV-2 QuantiVac ELISA (IgG) enables quantitative measurement of IgG antibodies against S1/RBD using a six-point calibration curve. The antibody concentration is measured in standardised binding antibody units (BAU/ml) based on the international reference material (NIBSC code: 20/136).
Measurement of the neutralising activity of anti-S1/RBD antibodies enables confirmation of their functionality in inhibiting binding of S1/RBD to the host ACE2 receptors and thus preventing infection. The SARS-CoV-2 NeutraLISA provides fast and economical determination of the inhibiting effect of anti-SARS-CoV-2 antibodies in patient samples, serving as a surrogate virus neutralisation test. It demonstrates a high (98.6%) agreement with the gold standard plaque reduction neutralisation test. The assay takes just two hours to perform and is automatable, making it suitable for high-throughput diagnostics.
T-cell analysis
T-cell immunity, in particular against the spike protein, is associated with strong protection against SARS-CoV-2 and plays a particularly important role in patients who not exhibit measurable concentrations of specific anti-bodies. The T-cell-mediated cellular immune response to SARS-CoV-2 can be determined using the Quan-T-Cell System, an interferon gamma release assay (IGRA). The test is performed on heparinised whole blood samples, circumventing the need to prepare purified peripheral mononuclear cells (PBMCs). The T cells in the samples are stimulated using spike protein-based antigens in the provided tubes and the released IFN- is subsequently measured using a fully automatable quantitative ELISA. The EUROIMMUN assay is well established in the research field and is also suitable for routine in vitro diagnostics.
