ERVW-1 and infection: In West Africa, where CRF02_AG plays a major role, subtype A constituted 52.6% of infections for full length and similar percentages for gag and env. However, subtype G constituted 78.7% for pol. In the other regions, which had fewer CRF infections, there was less change in HIV-1 subtype proportions following reassignment of CRFs to “pure” HIV-1 subtypes (Figure 2 and Supplementary Material, pp.