Support for Correlates of Protection efforts associated with the C113 phase 2b trial of MTBVAC in IGRA+, HIV- African adults and adolescents

A tuberculosis vaccine candidate is about to be tested in a large-scale trial in Africa, and this grant ensures that blood samples from every participant are collected, shipped, and stored for a decade so scientists can later figure out *why* it works. TB kills more people than any other single infectious disease, yet no vaccine reliably prevents it in adults and adolescents. The leading candidate, BCG, protects infants but offers inconsistent protection in older age groups. This trial tests a new vaccine, MTBVAC, in people who already carry a latent TB infection—the very group most at risk of developing active, contagious disease. If the vaccine proves effective, the stored blood specimens will allow researchers to identify the specific immune responses that correlate with protection. That knowledge is currently missing. Identifying a correlate of protection would transform TB vaccine development. Instead of running decade-long, multi-thousand-person efficacy trials for every new candidate, researchers could use a simple blood test to quickly screen which vaccines are most promising. This would dramatically accelerate the pipeline for a vaccine that could prevent millions of deaths. The grant itself does not test the vaccine—it builds the infrastructure to learn from the trial, whatever its outcome.