Tuberculosis (TB) is an infectious disease caused by Mycobacterium tuberculosis. One third of the world population has latent TB infection (LTBI), that don’t feel sick, don´t have symptoms and can´t spread TB but may develop active TB, if left untreated. There are many risk factors that lead to progression from LTBI to active TB disease such as HIV infection, underweight or malnourished persons. MycobacteriaspecificCD4 T cells in the tuberculous granuloma may control infection,through producing Interferon γ , interleukin 2 and tumour necrosis factor α (TNF α). The early diagnosis and proper treatment of persons withLTBI is an essential component of TB prevention and control. TheQuantiferon-TB gold (QFT-G) test was approved by the Food and DrugAdministration (FDA) for diagnosis of LTBI which is more specific thanTST in BCG vaccinated subjects. The BCG vaccine may preventreactivation of LTBI. Vaccines under evaluation include; prime-boostvaccines, Subunit vaccines, DNA vaccines, Modifying currently availableBCG vaccines, or Attenuated vaccine.