mRNA Vaccine-Elicited SARS-CoV-2-Specific T cells Persist at 6 Months and Recognize the Delta Variant.

Little is known about the decay kinetics of COVID-19 vaccine-elicited SARS-CoV-2 specific T cells. In this study we show a modest decline in the frequency of these T cells at 6 months and demonstrate robust expansion in response to antigen and recognition of spike peptides from the delta variant.