Multicenter trial of Towne strain attenuated virus vaccine in seronegative renal transplant recipients.

The Towne strain of attenuated CMV vaccine was compared with placebo in seronegative renal transplants who later received kidneys from seropositive donors. This was a double-blind, randomized, placebo-controlled trial conducted at 3 different institutions. The results were consistent with 2 prior studies, in that whereas mild CMV disease was only slightly and insignificantly reduced in vaccine recipients, severe disease was markedly reduced. In the current study, all 4 severe cases of CMV disease occurred in placebo recipients, for an incidence of 17%, versus 0% in vaccine recipients (P < 0.03). Thus, prior immunization rendered seronegative patients more resistant to the effects of CMV infection.