To prove the development of spike-specific T cells in vitro, we investigated the T cell response by performing IFN-γ- and chemokine-release assays with samples from infection-naïve vaccinees and SARS-CoV-2-infected individuals five weeks after vaccination (n=17) or breakthrough infection with the Omicron BA.1 variant (n=8), respectively. Here, IFNG is linked to infection.