Donor vaccination to minor HA as a potential strategy to separate GVHD from GVL and pathogen-specific immunity after BMT. Donors are vaccinated with recipient minor Histocompatibility Antigens (mHA) to generate memory T cells (T_m). Stem cell grafts are subsequently harvested and naive T cells (T_n) depleted such that only stem cells (CD34⁺) and memory T cells with specificity for recipient hematopoiesis (ie, leukemia) and pathogens are transferred.