Cutting Edge: T Cell Responses to B.1.1.529 (Omicron) SARS-CoV-2 Variant Induced by COVID-19 Infection and/or mRNA Vaccination Are Largely Preserved

• Published in: The Journal of immunology (1950) Vol. 208; no. 11; pp. 2461 - 2465
• Main Authors: Jergović, Mladen, Coplen, Christopher P., Uhrlaub, Jennifer L., Beitel, Shawn C., Burgess, Jefferey L., Lutrick, Karen, Ellingson, Katherine D., Watanabe, Makiko, Nikolich-Žugich, Janko
• Format: Journal Article
• Language: English
• Published: England 01.06.2022
• Subjects: Antibodies, Viral; COVID-19 - immunology; COVID-19 - prevention & control; COVID-19 Vaccines - immunology; Humans; Immunity, Cellular; Interleukin-2 - genetics; mRNA Vaccines - immunology; SARS-CoV-2; T-Lymphocytes - immunology; Vaccination; Vaccines, Synthetic
• ISSN: 0022-1767; 1550-6606; 1550-6606
• DOI: 10.4049/jimmunol.2200175

Several studies have demonstrated that the SARS-CoV-2 variant-of-concern B.1.1.529 (Omicron) exhibits a high degree of escape from Ab neutralization. Therefore, it is critical to determine how well the second line of adaptive immunity, T cell memory, performs against Omicron. To this purpose, we analyzed a human cohort (n = 327 subjects) of two- or three-dose mRNA vaccine recipients and COVID-19 postinfection subjects. We report that T cell responses against Omicron were largely preserved. IFN-γ–producing T cell responses remained equivalent to the response against the ancestral strain (WA1/2020), with some (∼20%) loss in IL-2 single or IL-2+IFN-γ+ polyfunctional responses. Three-dose vaccinated participants had similar responses to Omicron relative to post–COVID-19 participants and exhibited responses significantly higher than those receiving two mRNA vaccine doses. These results provide further evidence that a three-dose vaccine regimen benefits the induction of optimal functional T cell immune memory.