Designing a vaccine for tuberculosis

摘要

Tuberculosis is a disease of superlatives. Mycobacterium tuberculosis causes more deaths annually than any other infectious agent. Globally, it is one of the major pathogens associated with HIV disease. The tuberculosis vaccine, BCG, has been given to more people than any other vaccine. However, although this vaccine confers clear benefit against disseminated childhood tuberculosis, its efficacy against adult pulmonary disease has varied widely in different clinical trials. Curiously, protection induced by BCG seems to improve with increasing distance from the equator. In a large randomised controlled trial in Madras, southern India, and a large observational study in Malawi, BCG was no better than saline. It would be good to do better.