Sequential immunization with long and short constrained V3-peptide immunogens is described. 18–19 residue loop priming peptides followed by 10–14 residue loop focusing peptides were used. The protocol was designed to focus the immune response on the V3 tip of HIV-1 gp120. The immunofocusing protocol resulted in an increased percentage of Abs recognizing the V3 tip. The sequential approach was superior to repeated immunization with the same peptide.