Evaluation of the TB-specific IFN-γ-producing cell profiles specific for PPD, CFP10 and ESAT6 antigens in the macaques enrolled in study 2 revealed frequencies prior to treatment similar to previously published studies where cynomolgus macaques had been infected with the Erdman strain of M. tb [28,29] and act as confirmation that all animals were infected and initiated an immune response to infection. Here, IFNG is linked to infection.