Trial will enroll up to 240 subjects (160 recipients and 80 donors). Qualified donors and/or CMV-seropositive recipients (donor/recipient pairs or recipient-only subjects) will be assigned randomly to receive either a CMV vaccine or a placebo vaccine. Donors will receive 3 vaccines prior to donation and recipients will receive 1 vaccine pretransplant and up to three vaccines posttransplant. Recipients will be followed for up to 1 year after transplant to evaluate the safety of the vaccine and to see if there is a clinical benefit in the group that received the CMV vaccine. The incidence rates of CMV infection, disease, and other complications from immunosuppression and/or transplantation will be studied.