In 2023, Tuberculosis (TB) caused more deaths worldwide than any other infectious disease. It is caused by the bacterium Mycobacterium tuberculosis, and although largely unheard of in the developed world by the late 20th century, cases have been rising globally in recent years and it continues to place an enormous social and economic burden on much of the developing world.
Although often thought of as a lung disease, TB can infect other parts of the body, including the brain and the spine.
Currently the only licensed vaccine against TB is Bacillus Calmette-Guérin (BCG), an old vaccine which has been given to millions of people for over a century. BCG is a weakened form of Mycobacterium bovis, which is very similar to Mycobacterium tuberculosis and is normally given as an injection in the skin at birth in areas with endemic TB. The vaccine is 70-80% effective against the most severe forms of TB, such as TB meningitis, but it is much less effective in preventing the form of TB that affects the lungs.
Although BCG is safe to give to infants, it does not provide life-long protection and drugs against TB are not enough to stop the financial and social burdens of TB disease. An effective vaccine is urgently needed to reduce the spread of infection, prevent progression to active disease, and save lives.
Professor Helen McShane, Professor of Vaccinology at Oxford's Jenner Institute, explains: 'Tuberculosis, in the 21st century, still kills more people than any other infectious disease. We urgently need to develop effective vaccines, as the most cost-effective way to control this epidemic.