Trivalent cocktail of de novo designed immunogens enables the robust induction and focusing of functional antibodies in vivo

protein design has been increasingly successful in expanding beyond nature’s sequence and structural space. However, most designed proteins lack biological function, in part due to the structural complexity required for functional purposes. An important domain where protein design has raised expectations was on the induction of precise antibody responses that may lead to improved vaccines. Here, we showcase two computational design approaches to stabilize irregular and discontinuous binding motifs in designed immunogens and tested them for the induction of respiratory syncytial virus neutralizing antibodies . The designs mimic the native conformations of the neutralization epitopes with sub-angstrom accuracy. , cocktail formulations of the immunogens induce robust neutralizing serum responses targeting three epitopes, and re-focus pre-existing antibody responses towards neutralization epitopes. Our work provides a blueprint for epitope-centric vaccine design for pathogens that have frustrated traditional vaccine development efforts, and a general methodological pipeline to create novel proteins with functional sites within tailored protein topologies.