Prospects for elimination of childhood tuberculosis: the role of new vaccines

Control of childhood tuberculosis must be considered in the context of active tuberculosis disease among adults, who form the main reservoir of transmission. The elimination target of the Stop TB Partnership is a reduction of global incidence to less than one case per million per year by 2050. There is an urgent need for a new, safe and effective tuberculosis vaccine that prevents all forms of tuberculosis, in all age groups and in HIV-infected people. Bacillus Calmette-Guérin (BCG) vaccination protects against disseminated forms of childhood tuberculosis, but protection is variable against pulmonary tuberculosis and adult disease. 14 new tuberculosis vaccines have entered human clinical trials, including viral-vectored vaccines, recombinant fusion proteins, recombinant BCG vaccines and inactivated whole or fragmented mycobacteria. Effective pre-exposure and postexposure vaccination, in conjunction with mass campaigns, is the most promising tuberculosis control strategy to approach the elimination target by the middle of the 21st century.