The status of tuberculosis vaccine development.

Tuberculosis represents the leading global cause of death from an infectious agent. Controlling the tuberculosis epidemic thus represents an urgent global public health priority. Epidemiological modelling suggests that, although drug treatments for tuberculosis continue to improve, WHO timelines to control the spread of the disease require a new vaccine capable of preventing tuberculosis, particularly in adolescents and adults. The spread of strains resistant to multiple drugs adds additional urgency to the vaccine development effort yet attempts to develop new vaccines with wider applicability and better, longer-lasting efficacy than BCG-the only tuberculosis vaccine licensed for use globally-have proven challenging. Results from clinical efficacy trials, particularly a completed, phase 2b trial for preventing tuberculosis disease in people infected with Mycobacterium tuberculosis using the adjuvanted protein subunit vaccine M72/AS01E give hope. We review the current status of tuberculosis vaccine candidates and outline the diversified vaccine development that are underway.