Tuberculosis (commonly known as “consumption”) is an ancient infectious disease that affects all organs of the body (mostly tuberculous meningitis in children and pulmonary tuberculosis in adults). Before the introduction of BCG vaccine (made from live bovine Mycobacterium tuberculosis, inoculation of which is equivalent to an artificial local infection), tuberculosis was a major cause of death from human disease, and only after 1921, with the widespread use of BCG vaccine, the threat of death from tuberculosis was eliminated. Therefore, the role of BCG vaccine is certain. Does BCG vaccination guarantee that one will not contract TB in the future? It is difficult to say. Because the success rate of BCG vaccination is only 80% at most, and rabbit immunity can only last for 5-10 years, there is still a possibility that newborns will be infected with outside tuberculosis bacilli later as their immunity declines after the first vaccination. It is for this reason that in the past we advocated a repeat BCG vaccination for children aged 7-15 years who had a negative tuberculin test (i.e., unsuccessful immunization) to strengthen immunity. However, it has been proven that the re-vaccination is not effective in preventing tuberculosis. Since 1997, we have abolished this practice of repeat vaccination. Is it possible to prevent tuberculosis in adults by BCG vaccination? The answer is no. The reason is that many adults are already naturally infected with Mycobacterium tuberculosis and there is really no need for another artificial infection (BCG vaccination).