Abstract Accelerating B Cell and Antibody Molecular, Functional and Structural Analysis in Sequential bnAb-inducing Env Immunogen Clinical Trials Development of an effective HIV vaccine is essential for achieving long-term immunity to prevent new HIV infections globally. A successful HIV vaccine regimen will likely need to induce potent broad neutralizing antibodies (bnAbs) to contemporary circulating viral strains. New HIV Env immunogen designs, guided by knowledge of bnAb interactions with envelope epitopes and their B cell clonal lineage development in natural HIV infection, have entered first in human studies in the HVTN. These phase 1 “discovery” trials rely on more efficient, near real-time molecular, functional, and structural analyses of B cell and antibody responses. To meet this expectation, the HVTN Laboratory Center proposes to continue expansion and improvement of laboratory and analytical capacity that can accelerate iterative evaluation of bnAb-inducing vaccine candidates. The supplemental funds for the HVTN Laboratory make it possible to fully access evolving immunologic, molecular, and structural technology, which deepens our laboratory analyses and increases throughput of data generation and interpretation. To accomplish this, we will sustain the employment of additional dedicated trained staff and equipment to increase laboratory throughput of B cell repertoire, antibody binding with epitope mapping, neutralization, and antibody structural analyses. These funds will continue to enable efficient laboratory operations and integration of the scientific partnerships between key investigators at Fred Hutch, Duke University, and the Scripps Research Institute.