ERVW-1 and HIV-1 infection: A case–control study designed to identify immune correlates of reduced infection risk demonstrated that high levels of antibodies (Abs) directed against the V1V2 region of the virus gp120 envelope glycoprotein were associated with a decreased risk of HIV-1 infection, while high levels of Env-specific plasma IgA were associated with an increased risk (Haynes et al., 2012).