CD8A and influenza: As frequencies of Epstein–Barr virus, influenza-, and SARS-CoV-2-specific CD8 T cells reach up to 1% of all CD8 T cells,46 we allocated the donors into LF (NLV-T cells <1%) and HF (NLV-T cells >1%) groups, to allow comparison of cells without and with NLV-T cell expansion.