Vaccines for Cytomegalovirus

Cytomegalovirus (CMV) is a leading cause of congenital infection worldwide and therefore is recognized as an important target for vaccine development. Data from natural infections and work done with animal models, including models of congenital infection, provide the rationale for their development. CMV vaccine evaluations were begun in the mid-1970's with an attenuated live virus vaccine, Towne, but this vaccine has not consistently provided protection. Most recently, data from a trial with a subunit glycoprotein B (gB) vaccine administered with the adjuvant MF59 became available. This trial, conducted in post-partum women, demonstrated that the vaccine decreased CMV infections, increasing optimism that a protective CMV vaccine could be developed. Other approaches for CMV that have entered clinical trials include replicons, DNA vaccines, prime boost strategies, and chimeric live viruses. The replicon vaccine included gB and the T cell targets phosphoprotein (pp)65 and Immediate Early (IE)1 while the DNA vaccine was given with a new adjuvant and included gB and pp65. The optimal composition for a CMV vaccine remains to be defined but trials continue with the gB vaccine and others.