Recovery of functional antiviral responses. (A) Functional response to EBV. The number of cells secreting interferon-γ in response to stimulation with donor EBV-LCL in ELISPOT assays are shown at varying time points after SCT. Dose-level 1 patients are shown in the top panel and level 2 patients in the bottom panel. (B) Functional response to CMV. The number of cells secreting interferon-γ in response to stimulation with donor PBMCs expressing a pp65 transgene in ELISPOT assays are shown at varying time points after SCT. Patients at dose-level 1 are shown in panel i and dose-level 2 patients in panel ii. Viral reactivations are indicated by the arrows.