BCG: From veins to correlates.

In this issue of Cell Host & Microbe, Darrah et al. define immune responses against Mycobacterium tuberculosis (Mtb) infection following intravenous Bacille-Calmette Guérin (BCG) vaccination of nonhuman primates. The results provide candidate correlates of protection for examination in clinical trials of TB vaccines against Mtb infection and tuberculosis (TB) disease.