A Cytomegalovirus Vaccine for Transplantation: Are We Closer?

Cytomegalovirus (CMV), a betaherpesvirus, causes significant human morbidity and mortality. It is present in at least 60% of the US population [1], with a prevalence of >90% in high-risk groups, including men who have sex with men [2, 3]. In immunocompetent hosts, CMV infection is usually asymptomatic, but it persists throughout an individual's lifetime and has the potential to reactivate and cause disease. CMV also causes significant disease in newborns, which can result in sensorineural hearing loss, other central nervous system abnormalities, and death. In immunocompromised individuals, CMV is the most common viral cause of severe disease, including gastrointestinal manifestations and pneumonia in the transplant population and, in addition, retinitis in HIV-positive individuals [4,5].