ERVW-1 and HIV-1 infection: Vaccine efficacy was associated with non-nAbs to V1V2 regions of HIV-1 Env, Fc-mediated effector responses, high levels of V2-specific antibodies mediating ADCC (antibody-dependent cellular cytotoxicity), HIV-1 V2-specific IgG3 antibodies, and Env-specific CD4+ T-cell responses, while Env IgA antibodies were seen to directly correlate with HIV-1 infection [8,70].