ERVW-1 and infection: The IgG subclass distribution for V1V2 or V3 antigens was more balanced than the distribution seen for gp140 and gp120 antigens (Fig 1A). The dynamics of the binding antibody response from 6 to 36 months following infection (S1 Fig) showed significant increases in the proportion of total IgG and IgG1 to Env overtime.