The BCG vaccine has been widely available for several decades. It is easy and cheap to produce, and when given to neonates or young children it is effective in preventing severe manifestations of disease such as meningeal tuberculosis and miliary tuberculosis. However, in terms of the capacity of the vaccine to protect adult humans it shows a wide range of efficacy, including zero levels of protection. Due to the general realization that BCG is losing its protective effect, particularly in terms of preventing adult-onset tuberculosis, a major effort has been made to try to develop new alternative vaccines. One such candidate, Mtb72F/AS02A, is a polyprotein derived from two known M. tuberculosis antigens adjuvanted with AS02A. Mtb72F/AS02A is a candidate TB vaccine under development for two indications: prevention of primary TB infection in young children in highly endemic areas and as an adjunct to treatment for TB in adolescents and adults.