SARS-CoV-2 vaccination induces immunological T cell memory able to cross-recognize variants from Alpha to Omicron

Abstract

We address whether T cell responses induced by different vaccine platforms (mRNA-1273, BNT162b2, Ad26.COV2.S, NVX-CoV2373) cross-recognize early SARS-CoV-2 variants. T cell responses to early variants were preserved across vaccine platforms. By contrast, significant overall decreases were observed for memory B cells and neutralizing antibodies. In subjects ∼6 months post-vaccination, 90% (CD4 ⁺) and 87% (CD8 ⁺) of memory T cell responses were preserved against variants on average by AIM assay, and 84% (CD4 ⁺) and 85% (CD8 ⁺) preserved against Omicron. Omicron RBD memory B cell recognition was substantially reduced to 42% compared to other variants. T cell epitope repertoire analysis revealed a median of 11 and 10 spike epitopes recognized by CD4 ⁺ and CD8 ⁺ T cells, with average preservation > 80% for Omicron. Functional preservation of the majority of T cell responses may play an important role as second-level defenses against diverse variants.

Graphical Abstract

Abstract

Human memory T cells induced by SARS-CoV-2 vaccines maintain the ability to recognize viral variants, including the omicron variant.