We report that stimulation of naive T cells with autologous irradiated peripheral mononuclear cells pulsed with a tetanus-diphtheria Td vaccine renders them cross-reactive with a peptide pool consisting of 25 known SARS-CoV-2-specific CD8+ T cell epitopes related by similarity with antigens in Td vaccines (TDX pool). This evidence concerns the gene CD8A and diphtheria.