CD4 and infection: In vectored vaccine studies, rhesus cytomegalovirus vector expressing HIV-1 Gag, Pol, Nef, Env, RT, and integrase sequences demonstrated a high frequency of CD69+IFNγ+ and/or CD69+TNFα+ CD4+ and CD8+ effector memory T cell response that correlated to control of highly pathogenic SIVmac239 infection after mucosal challenge (119).