New mRNA vaccine aims to shield transplant patients from dangerous virus

Copied word for word from the study's registry entry, so the wording is the study team's rather than ours.

Inclusion Criteria: * Receipt of an allogeneic HCT. * CMV-seropositive, defined as a documented positive test for anti-CMV IgG. * High-risk for CMV: HCT from related, unrelated, or haploidentical donor with post-transplant cyclophosphamide for graft-versus-host-disease (GVHD) prophylaxis; or HCT from related or unrelated donor with at least one mismatch at any of the following human leukocyte antigen (HLA) gene loci (HLA-A, B, C, and DRB1); or HCT from related or unrelated donor with myeloablative conditioning. * Persons of nonchildbearing potential or of childbearing potential with negative urine or serum pregnancy test on the day of first study injection. * Persons of childbearing potential who have practiced adequate contraception or have abstained from all activities that could result in pregnancy for at least 28 days prior to the first dose. * Persons of childbearing potential who have agreed to continue adequate contraception or abstain from all activities that could result in pregnancy through 3 months after last study injection. * Persons who are not currently breast/chestfeeding. * Willingness to comply with study procedures and provide written informed consent. Exclusion Criteria: * History of a diagnosis or condition that, in the judgment of the Investigator, may affect participant safety, assessment of safety endpoints, assessment of immune response, or adherence to study procedures. * A documented positive human immunodeficiency virus (HIV) test. * Treatment with alemtuzumab (Campath®), antithymocyte globulin (ATG), or any equivalent in-vivo T cell depleting agent within 12 months. * HCT with ex-vivo T cell depletion. * Low risk for CMV: HCT from related or unrelated donor with reduced intensity conditioning (RIC) and no other high-risk features. * History of prior hematopoietic cell transplantation within 12 months. * Receipt of prior investigational CMV vaccines or participation in another CMV therapeutic study that may interfere with study outcome measures as determined by the Investigator. * Suspected or known allergic reaction to any component of any mRNA vaccine or its excipients.