T cell immune responses to SARS-CoV-2 and variants of concern(Alpha and Delta)in infected and vaccinated individuals

Our understanding of immune responses to SARS-CoV-2 and variants of concern(VOCs)has been primarily acquired through analysis of Spike-specific IgG responses.However,a more comprehensive understanding of the breadth and longevity of immune responses after infection and vaccination requires analysis of cellular immunity.Herein,we report on T cell immunity in infected and vaccinated individuals,identifying CD4+/CD8+T cell cytokine responses to SARS-CoV-2 and variant peptides(Alpha,B.1.1.7 and Delta,B.1.617.2).