Neutralization of WT and chimeric viruses by SF162gp140-elicited antibodies. The effect of replacing the V1 loop of the YU2, JRFL, 89.6, HxB2, and ADA viruses with that of SF162 on the susceptibilities of these viruses to neutralization by antibodies elicited in rhesus macaques immunized with SF162 gp140 (12) is shown. ○, SF162WT; ▪, YU2 WT, JRFL WT, 89.6 WT, HxB2 WT, or ADA WT; □, YU2, JRFL, 89.6, HxB2, or ADA expressing the V1 loop; ⧫, virions pseudotyped with murine leukemia virus Env.