Notably, persistence of immunity to CMV in R- KTRs experiencing primary infection was significantly impaired, and in R+ KTRs CMV reactivation control was associated with increased frequency of CD28lo KLRG1hi CD127lo HLA-DRhi CD8+ T cells, which have the potential to differentiate into long-lived effector cells to provide durable immunosurveillance. Here, CD8A is linked to infection.