Binding antibodies to the V1/V2 region of the envelope protein, IgG3 subclass V1/V2-specific antibodies, polyfunctional Env-specific CD4 T cells, low mucosal Env-specific IgA, and antibody-effector activities all show evidence of being associated with reduced risk of infection [2, 8–14]. Here, ERVW-1 is linked to infection.