SARS-CoV-2-specific T cell responses: a comparative analysis between QuantiFERON SARS-CoV-2, T-SPOT.COVID, and an in-house Omicron ELISpot

• Published in: Journal of virological methods Vol. 327; p. 114949
• Main Authors: Mak, Willem A., Visser, Wendy, Koeleman, Johannes G.M., Ong, David S.Y.
• Format: Journal Article
• Language: English
• Published: Netherlands Elsevier B.V 01.06.2024
• Subjects: Adult; Cohort Studies; COVID-19; COVID-19 - diagnosis; COVID-19 - immunology; COVID-19 Vaccines - immunology; ELISpot; Enzyme-Linked Immunospot Assay - methods; Female; Health Personnel; Humans; IGRA; Immunity; Interferon-gamma - immunology; Interferon-gamma Release Tests - methods; Male; Middle Aged; SARS-CoV-2; SARS-CoV-2 - immunology; T cells; T-Lymphocytes - immunology; COVID-19; SARS-CoV-2; T cells; Immunity; ELISpot; IGRA
• ISSN: 0166-0934; 1879-0984
• DOI: 10.1016/j.jviromet.2024.114949

T cell immunity plays a pivotal role in mitigating the severity of coronavirus disease 2019 (COVID-19). Therefore, reliable functional T cell assays are required to evaluate severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2)-specific T cell immunity in specific patient populations. We recruited a cohort of 23 healthcare workers who received their bivalent Omicron BA.1 / ancestral mRNA booster vaccination or were infected with the Omicron variant at a median of 144 days and 227 days before blood collection, respectively. In this cohort, we compared the performances of two widely utilized commercial SARS-CoV-2 interferon-gamma release assays (IGRAs), i.e., QuantiFERON SARS-CoV-2 and T-SPOT.COVID, and an in-house designed Omicron enzyme-linked immunospot (ELISpot). The QuantiFERON SARS-CoV-2 and T-SPOT.COVID assays detected SARS-CoV-2 spike-specific T cells in 34.8 % and 21.7 % of participants, respectively. Moreover, our in-house designed ELISpot that included Omicron BA.4 and BA.5 full-spike peptides detected T cell responses in 47.8 % of participants and was strongly associated with the T-SPOT.COVID. The evaluation of SARS-CoV-2 T cell immunity using commercially accessible assays may yield disparate outcomes as results from different assays are not directly comparable. A specific Omicron ELISpot should be considered to assess Omicron-specific T cell immunity. •Observations of quantified T cell responses strongly depend on the IGRA assay used.•The in-house Omicron ELISpot detects more T cell responses than commercial IGRAs.•Results of the in-house Omicron ELISpot strongly associate with the T-SPOT.COVID.