Vaccination of rhesus macaques with rhesus cytomegalovirus strain 68-1 expressing SIV proteins (RhCMV/SIV) results in stringent control of SIV replication. Approximately fifty percent of vaccinated rhesus macaques exhibit robust control of SIV replication following challenge and eventually clear the virus entirely. However, the mechanism of control and clearance of SIV in strain 68-1 RhCMV/SIV-vaccinated rhesus macaques is unknown. Previous work demonstrated that strain 68-1 RhCMV/SIV vaccination elicits a unique SIV-specific CD8+ T cell response characterized by novel epitope targeting, universal responses elicited regardless of MHC genotype, and wide breadth. We hypothesized this distinct SIV-specific CD8+ T cell response results from unique patterns of MHC restriction.