Lin R, Wang Y, Huang F, et al. - To compare the impact on viral infections and graft-vs-host disease (GVHD) prophylaxis following haplo-hematopoietic stem cell transplantation (HSCT), 408 patients were recruited in this multicenter study to assess the efficacy of 7.5 mg/kg vs 10.0 mg/kg rabbit antithymocyte globulin (ATG, ImtixSangstat). The 1-year incidence of Epstein-Barr virus (EBV) DNAemia in the 7.5 mg/kg and 10.0 mg/kg groups was 20.7% and 40.0%, respectively. In the 7.5 mg/kg and 10.0 mg/kg ATG groups, respectively, the 100-day cumulative incidence of grade II to IV aGVHD was 27.1% and 25.4%. The 2-year incidence of chronic GVHD in the 7.5 mg and 10.0 mg groups was 34.6% and 36.2%. The 3-year overall survival posttransplantation and the disease-free survival was 69.5% and 63.5% and 62.2% and 60.3% in the 7.5 mg/kg and 10.0 mg/kg groups, respectively. The counts of EBV- and CMV-specific cytotoxic T cells (CTLs) were greater in the 7.5 mg/kg group vs 10.0 mg/kg group early posttransplantation. For GVHD prophylaxis, 7.5 mg/kg ATG vs 10.0 mg/kg, was related to decreased EBV and CMV infections without elevated incidence of GVHD in haplo-HSCT, most likely due to influencing EBV- and CMV-specific CTLs.