Motif-optimized subtype A HIV envelope-based DNA vaccines rapidly elicit neutralizing antibodies when delivered sequentially

► Immunization with naturally evolving env genes, given sequentially, is promising. ► Motif-optimized env sequences were superior to wild type for neutralizing antibodies. ► Simultaneous boosting with DNA and protein at different sites enhanced antibodies. ► Antibodies that neutralized heterologous HIV-1 isolates were obtained in rabbits.