Abstract Objective Cytomegalovirus (CMV) infection is a common opportunistic after allogeneic hematopoietic cell transplant (alloHCT). We explored whether change in CMV cell-mediated immunity (CMV CMI) during the first month predicts risk of development and all-cause mortality. Methods This was follow-up analysis using data from REACT study, multicenter prospective observational study CMV-serop...