Validation of 'Corona-T-test' for Assessment of SARS-COV-2-specific T-cell Response After COVID-19 or Vaccination

Validation of Specificity, Sensitivity, and Accuracy for an ELISpot-based In-vitro Diagnostic (IVD) Kit 'Corona-T-test' for Assessment of SARS-COV-2-specific T-cell Response

Accuracy validation of the designed and manufactured ELISpot-based in vitro diagnostic 'Corona-T-test' for detection of SARS-CoV-2-specific T cells.

The investigators enrolled three independent cohorts of vaccinated (n = 69), convalescent (n = 50), and healthy but unvaccinated individuals (n = 101). Further, they estimated the T cell response to the designed peptide antigen panel, as measured by the manufactured ELISpot-based in vitro diagnostic 'Corona-T-test' to detect SARS-CoV-2-specific T cells.

Non-specific inclusion criteria

• Participants aged 18 and above
• Participants agreeing to follow the study procedures
• Participants able to understand the purpose, nature, and methodology of the study
• Participants having signed the informed consent

Healthy donors inclusion criteria

• No self-reported COVID-19 infection
• No vaccination against COVID-19
• No immunoglobulin (Ig) IgM or IgG antibodies against SARS-CoV-2 by three tests (IgM to SARS-CoV-2 detection: "SARS-CoV-2-IgМ-ELISA-BEST", Ref #D-5502, IgG to SARS-CoV-2 S protein detection: "SARS-CoV-2-IgG-quantity-ELISA-BEST", "Vector-Best", Ref #D-5505), IgG to SARS-CoV-2 N protein detection: "SARS-CoV-2 IgG Reagent Kit", ARCHITECT, Abbott Laboratories, EU)

Convalescents inclusion criteria

• Self-reported COVID-19 infection
• PCR confirmed COVID-19 in a period 14-45 days before recruitment
• Detectable IgG antibodies against SARS-CoV-2 (IgG to RBD domain of SARS-CoV-2 S protein detection: "SARS-CoV-2-IgG-ELISA", "National Medical Research Center for Hematology", Moscow, Russia. Ref #K153G)

Vaccinated inclusion criteria

• SARS-CoV-2 vaccination with 'Sputnik V' (Gam-COVID-Vac) in a period 7-14 days after the second vaccination before recruitment
• Detectable IgG antibodies against SARS-CoV-2 (IgG to receptor-binding domain (RBD) domain of SARS-CoV-2 S protein: "SARS-CoV-2-IgG-ELISA", "National Medical Research Center for Hematology", Moscow, Russia. Ref #K153G)

Exclusion criteria

- Age under 18 y.o.