Will we be treating tuberculosis with vaccines in the XXI century?

The pillars for the control of tuberculosis are early diagnosis, appropriate treatment and prevention. After the discovery of the bacteriologically based treatment of tuberculosis halfway through the last century, various therapeutic regimens were established, allowing us to cure the vast majority of patients. However, it must be said that very little progress has been made in this area in recent decades. Prevention of tuberculosis remains focused on measures for avoiding contagion, chemoprophylaxis and BCG vaccination. Unlike the situation with other diseases such as smallpox, poliomyelitis, etc., where vaccines have led to control and even, in some cases, eradication, the role of the BCG vaccine has been constantly under discussion since it was introduced because, in addition to interfering with the predictive value of the tuberculin test, it has not managed to significantly modify the epidemiology of tuberculosis. The efficacy of the vaccine is very variable (0%–80%), it does not prevent tuberculosis infection and it does not protect the infected patient. The protection it does confer consists basically in preventing severe complications which may follow on from primary infection, such as meningitis and miliary tuberculosis. It is not recommended for systematic use in Spain. Despite this, we still believe that, as has already occurred with other diseases, an effective vaccine may be the right tool for achieving the anxiously awaited worldwide eradication of tuberculosis. In this respect, the discovery of the Mycobacterium tuberculosis genome and improved knowledge of the bacillus’ immunopathology has opened new avenues of research into new vaccines for the prevention and treatment of tuberculosis. Over the past 20 years, enormous efforts and public and private financial resources have been poured into the search for and development of new vaccines in order to improve or replace the BCG. Great progress has been made in the last 15 years that has produced a good number of vaccines now in the clinical development phase. Furthermore, various centers, including some in Spain, have