Ten challenges for TB biomarkers

The availability of tuberculosis (TB) biomarkers of protection (or: “surrogate endpoints of protection against active TB” (Biomarkers Definitions Working Group, 2001)) would greatly facilitate and accelerate TB vaccine development and increase the likelihood of success. TB biomarkers of protection could determine which vaccines in clinical trials are the most efficacious; which vaccine candidates and strategies are the most promising in early stages in the preclinical development pipeline (including relevant antigens, antigen delivery, live vaccines); and which combination vaccines (prime/boost) would be the most effective. Here we discuss ten major challenges for biomarker identification and validation in TB. Current major roadblocks and critical limitations in understanding TB pathogenesis are highlighted, and new solutions and strategies proposed.