Our kits valuable in delineating SARS-CoV-2 immunity

One of many interesting papers by authors Ogbe et al., shows that the detection of T cell responses to SARS-CoV-2 is critically dependent on assay and antigen selection.

Using ex vivo IFN-gamma ELISpot and peptide stimulation, the authors demonstrated robust positive responses to S, N, M and other structural and accessory proteins in 168 individuals with PCR confirmed SARS-CoV-2 infection.

SARS-CoV-2-specific IFN-gamma responses were scarcely seen in any of the SARS-CoV-2 peptide pools as measured by ex vivo ELISpot assays in seronegative healthy control volunteers or in healthy pre-pandemic controls.

The authors conclude that IFN-gamma ELISpot is a valuable tool in defining the role of T cell immunity in recently infected individuals without cross-reactivity in unexposed people.

Finally, to explore the use of these T cells assays to identify people potentially exposed to SARS-CoV-2, the authors recruited a group of highly exposed healthcare workers working in acute medicine and
who had experienced symptoms compatible with COVID-19 but had not received PCR testing at the time of symptoms, or tested negative, and were subsequently seronegative. 30% of these healthcare workers showed effector T cell responses by ELISpot assay to S1, S2, M or NP.