Poor HCMV–specific T-cell reconstitution in csCMVi patients after discontinuation of letermovir. Samples from alloSCT recipients receiving letermovir prophylaxis until day +100 who controlled HCMV (controllers, blue) and those with csCMVi (brown) were compared using flow cytometry. (A) Heat map comparing the MMRs (csCMVi/controllers) of selected T-cell populations between the 2 cohorts. (B-E) Background-corrected median numbers (B) and frequencies (C) of HCMV–specific Th cells (CD4⁺IFN-γ⁺) as well as numbers (D) and frequencies (E) of cytotoxic T cells (CD8⁺IFN-γ⁺CD107a⁺). (A-E) Mann-Whitney U test and Benjamini-Hochberg procedure to test for an FDR of <0.2. (F,G) Background-corrected individual numbers of HCMV–specific (F) Th cells (CD4⁺IFN-γ⁺) and (G) cytotoxic T cells (CD8⁺IFN-γ⁺ CD107a⁺) on day +90 and day +210 are shown. (H-I) Background-corrected individual numbers of HCMV–specific (H) Th cells (CD4⁺IFN-γ⁺) and (I) cytotoxic T cells (CD8⁺IFN-γ⁺CD107a⁺) before and after csCMVi are displayed. (F-I) ∗P < .05, ∗∗P < .01, ∗∗∗P < .001 using paired Wilcoxon test. CD, cluster of differentiation; d, day; MMR, median-to-median ratio.