Includes bibliographical referencesTuberculosis (TB) vaccine candidates have been mostly ineffective and it remains unclear as to what constitutes protective host immunity. Despite high levels of IFN-γ at the site of disease, the Th1 cytokine associated with protection, many individuals still have progressive active TB. Whether a Th2-like immune response (IL-4; IL-4δ2; IL-9) can subvert protective host immunity requires clarification
