HLA-C and infection: These vaccines target the APCs and initiate immune responses through two major mechanisms: (1) the indirect infection of the APCs, which works through cellular damage mediated by viral infection to send danger signals and as well as costimulatory molecules to activate the APCs of bone marrow [130,136,137], and (2) the direct infection of the APCs, which is based on the processing of the antigens in the MHC pathways.