Multi-antigen CMV-MVA Triplex Vaccine in Reducing CMV Complications in Patients Previously Infected With CMV and Undergoing Donor Hematopoietic Cell Transplant

PRIMARY OBJECTIVES: I. To evaluate the safety and tolerability of CMV-MVA Triplex (multi-peptide CMV-MVA vaccine) in vaccinated hematopoietic cell transplant (HCT) recipients by assessing the following: non-relapse mortality (NRM) at 100 days post HCT, severe (grade 3-4) acute graft-versus-host disease (GVHD) (aGVHD), and grade 3-4 adverse events (AEs) (Common Terminology Criteria for Adverse Events \[CTCAE\] 4.0) probably or definitely related to the vaccination within 2 weeks from each vaccination. II. To determine if CMV-MVA Triplex reduces the frequency of CMV events defined as reactivation or CMV disease in allogeneic CMV positive HCT recipients (HCT-R+). SECONDARY OBJECTIVES: I. To characterize CMV reactivation and CMV disease in recipients of CMV-MVA Triplex compared to placebo by assessing time-to viremia (defined as number of days from transplantation to the date of \> 500 CMV gc/mL), duration of viremia, recurrence of viremia, incidence of late CMV viremia/disease (\> 100 and =\< 360 days post HCT), use of antiviral drugs (triggered by clinically significant viremia of \>= 1500 CMV gc/mL), cumulative number of CMV specific antiviral treatment days. II. To evaluate the impact of CMV-MVA Triplex on transplant related outcomes by assessing the incidence of acute GVHD (aGVHD), chronic GVHD (cGVHD), relapse, non-relapse mortality, all-cause mortality, infections. III. To determine 1) if CMV-MVA Triplex increases levels, function and kinetics of CMV-specific T cell immunity in vaccinated compared to placebo treated human leukocyte antigen (HLA) A\*0201, CMV seropositive HCT-recipients, 2) to determine whether vaccination induces adaptive natural killer (NK) cell population changes, and increase in the highly cytotoxic memory killer cell lectin-like receptor subfamily C, member 2 (NKG2C)+ NK cells, and 3) to explore GVHD biomarkers and compare between the vaccine and placebo groups. OUTLINE: Patients are randomized to 1 of 2 arms. ARM I: Patients receive multi-peptide CMV-MVA vaccine intramuscularly (IM) on days 28 and 56 post-HCT. ARM II: Patients receive placebo IM on days 28 and 56 post-HCT. After completion of study, patients are followed up for 1 year post-HCT.