Cytomegalovirus vaccine: persistence of humoral immunity following immunization of renal transplant candidates.

A randomized, placebo-controlled, double-blind trial of Towne live, attenuated cytomegalovirus (CMV) vaccine in renal transplant candidates underway since January 1979 has enabled us to assess the durability of humoral immunity after immunization. Among 53 seronegative subjects, Towne vaccine elicited a geometric mean indirect immunofluorescent (IF) antibody titre of 72.3, but titres in patients either not transplanted or given kidneys from seronegative donors declined substantially by one year postimmunization. Vaccine boosted the geometric mean IF antibody titre in 21 seropositive untransplanted subjects from 66.5 pre-immunization to 91.0 approximately three months later. Seventeen seronegative subjects given a seropositive kidney and 27 subjects seropositive before immunization experienced a sharp boost in geometric mean antibody titre posttransplant signifying reactivation of their own CMV strain or acquisition of virus from the donor kidney. These data indicate that Towne vaccine is immunogenic in renal transplant candidates but does not completely prevent posttransplant infections.