Although it is recommended that SARS-CoV-2-specific T-cells from the donor must share some HLAs with the recipient for proper presentation of the viral antigen to donor T-cell antigen receptors, previous studies have revealed that the use of virus-specific T-cells from donors sharing only one HLA was effective to treat severe viral infections after hematopoietic stem cell transplantation [60]. This evidence concerns the gene TARP and viral infectious disease.