First, a panel of newly generated HIV-1 neutralizing antibodies was comprehensively characterized as membrane-bound scFv inhibitors and found that GPI-anchored 10E8 was the most effective in the inhibitions of cell-free HIV-1 infection, cell-associated HIV-1 transmission, and viral Env-mediated cell–cell fusion. This evidence concerns the gene ERVW-1 and HIV-1 infection.