Table 3.

Potential novel HCMV vaccine strategies that have been explored in preclinical/animal model studies.

Novel HCMV Vaccine Approaches Currently in Preclinical Models
gM/gN (gcII Complex)	Major glycoprotein constituent of virion Majority of human sera contain anti-gcII antibodies gM/gN DNA vaccine immunogenic in mice
gH/gL/gO (gcIII Complex)	Target of neutralizing antibody response in setting of HCMV infection gH vaccine based on MCMV homolog protective in murine model when expressed as recombinant adenovirus
Essential/Nonstructural Gene Products as Novel CTL Targets	DNA polymerase (UL54) and helicase (UL105) as novel T-cell targets Protective in MCMV model when expressed as DNA vaccines
Prime/Boost Strategy	Prime with cocktail of plasmid DNA vaccines Boost with formalin-inactivated viral particles Induces “sterilizing immunity” in MCMV model
Bacterial Artificial Chromosome (BAC) Vaccines	Protective in MCMV model following delivery in bacteria with reconstitution of virus in vivo Protective in GPCMV model when administered as replication-disabled DNA vaccine Offers potential for specifically engineered vaccines
Peptide Vaccines	Effective in MCMV model following mucosal immunization with cholera toxin Allows simultaneous immunization against broad range of CTL epitopes: “polyepitope” vaccine Requires knowledge of HLA status; best suited to HCMV vaccination in transplantation setting?
“Dense Body” Vaccines	Noninfectious particles enriched for envelope glycoproteins and pp65, major subunit vaccine candidates Highly immunogenic in animal models Humoral and cell-mediated immune responses Can be engineered to express heterologous genes