Changing route: aerosol vaccine against tuberculosis

Mycobacterium tuberculosis infects a third of the world's population every year, causing 8·6 million new cases and 1·3 million deaths annually (1).BCG, a live-attenuated bacterial vaccine developed in the 1920s, is still used to vaccinate most children worldwide. Although BCG protects infants from severe disseminated disease, it cannot prevent infection. Especially in developing countries, pulmonary tuberculosis can develop mostly during adolescence, and has a high mortality rate in patients who are co-infected with HIV. So far, the development of vaccines that outperform BCG has been difficult.