Fig. 1: High-resolution immunofocusing.

a The ideal broadly-protective immunogen elicits high titers of antibodies directed against the epitope of interest while avoiding antibody responses against off-target immunodominant epitopes. In the context of highly mutable viruses, this target epitope is defined by the binding footprint of a broadly neutralizing antibody (shown in red). Green represents off-target, exposed antigenic surfaces that are still capable of eliciting antibodies, while gray represents masked regions. b–f Five major classes of immunofocusing strategies: cross-strain boosting, mosaic display, protein dissection, epitope scaffolding, and epitope masking.