The present invention is directed to a recombinant immunogenic polypeptide. The polypeptide includes a loop peptide inserted into an immunogenic scaffold protein. The loop polypeptide has an amino acid sequence which presents the 3074 mAb- or the 2219/2557 mAb-targeted epitope of the HIV gp120 protein and not other known epitopes of the HIV gp120 protein. When used as an immunogen, the polypeptide induces an antibody response which neutralizes heterologous HIV-1 viruses in a pattern similar to that observed for the 3074 mAb- or the 2219/2557 mAb-targeted epitope, respectively. Pharmaceutical compositions containing the immunogenic polypeptide as well as methods of making and using it are also disclosed.
