However, their previously identified correlates of risk of TB disease were not associated with an increased risk of M.tb infection in infants who became infected with the bacteria but did not progress to active TB. Most individuals infected with M.tb do not progress to full TB disease. Instead, infection is either eliminated or contained by the infected individual. This study improves understanding of the immune-related factors that drive infection and disease – necessary for an effective TB vaccine that is yet to be developed. The identification of specific correlates of protection for infection could support the development of a vaccine against M.tb that would then help prevent progression to TB disease.