Induction of an effective neutralizing antibody response will require that a vaccine deliver to the naïve B cell repertoire epitopes that are both immunogenic (i.e., possess favorable properties for B cell inductive pathways) and antigenic (i.e., available for high affinity antibody binding on functional Env spikes). Viral epitopes that are conserved among most viral strains are more likely to generate cross-reactive antibodies. In this regard, researchers have focused on a small number of human MAbs, from clade B HIV-1-infected individuals, that possess broadly cross-reactive neutralizing activity [17, 18] . The cognate viral epitopes for these MAbs have been well characterized and are being evaluated as vaccine immunogens. However, for reasons that are not completely understood, these conserved viral epitopes have either been poorly immunogenic or have elicited antibodies of restricted reactivity. Improvements are being sought by introducing specific structural alterations [19, 20] and by targeting autoreactive B cell pathways [21] . These and other efforts to improve the immunogenicity of conserved neutralization epitopes should remain a high priority. Workshop participants recognized the need to expand efforts to identify and characterize new MAbs, with special attention to MAbs from non-clade B HIV-1 infections. New technologies are now available that might afford an advantage for identifying novel antibody specificities that were previously undetected [22, 23] . In addition to this focus on MAbs, sera from selected HIV-1infected individuals that can broadly neutralize HIV-1 isolates should be studied in detail. New assays allow more precise mapping of the polyclonal antibody response in these sera to better understand the epitopes targeted [5, [24] [25] [26] . Such studies may reveal novel antibody specificities and their associated viral epitopes that could be useful for immunogen design.