A faster expansion of γδ T cells correlates with a faster infection resolution during CMV reactivation compared with primary infection. Forty-six renal allotransplantation patients, selected because they developed CMV infections, were divided according to the CMV serology of the recipient (R) and the donor (D) at the time of the graft. All patients displayed γδ T-cell expansion in their peripheral blood. (A) The time to γδ T-cell expansion was defined for each patient as the interval between the first day of CMV detection in the peripheral blood (pp65 antigenemia) and the day when γδ T cell levels plateaued.²²  (B) The duration of infection was defined as the number of weeks with a positive pp65 antigenemia. The long dashes in panels A and B represent the median value for each cohort. (C) 3 D⁺/R⁻ and 3 D⁻/R⁺ transplant patients who developed a CMV infection were monitored longitudinally for CD45RA and CD27 expression by Vδ2⁻ γδ T cells. Represented are the percentages of CD45RA⁺CD27⁻ cells in the Vδ2⁻ γδ T-cell population before and after CMV infection.