ERVW-1 and HIV-1 infection: In addition, among vaccine recipients with low IgA antibody responses to Env, HIV-1 infection risk was inversely correlated with IgG Env antibody avidity, antibody-dependent cellular cytotoxicity, neutralizing antibodies, and Env-specific CD4+ T cell responses [3], as well as with IgG to V3 linear peptides [6].