A seminal study by Ly et al[21] demonstrated that one of the key elements in the protection of guinea pigs by BCG vaccination relates to production of IFNγ along with TNFα post-infection in comparison to the unvaccinated animals, wherein, excessive quantities of TNFα are produced in the absence of IFNγ resulting in an inefficient control of bacillary growth accompanied by excessive pathology. Here, IFNG is linked to infection.