I learned when exposed to a case of 'open' TB on a long haul flight, that the BCG vaccine that my generation of kids were given at around age 11, is pretty nearly completely ineffective against pulmonary TB - the type that we all know and love - consumption - the scourge of Victorian life in the big cities. In fact , the BCG vaccine targeted meningitis caused by the same bacterium that causes tuberculosis of the lungs, mycobacterium tuberculosis.
In most patients, the immune reaction to the vaccine subsides 20 or so years after vaccination, however when they gave me the standard test for TB, the Mantoux tuberculin skin test, it was massively positive, suggesting either an active or recent TB infection. The local health authorities where I live then ran a Quantiferon Gold test; a test that is much more accurate, sensitive and can discriminate between people vaccinated with BCG and actual cases of TB. The Quantiferon Gold test came back reassuringly negative as did a second round of Quantiferon Gold testing six months later.
In summary, if the inexorable spread of TB in India and other developing nations is to be halted, the world needs an effective vaccine against pulmonary TB!
However, it is as well to remember that most people who are well fed are not susceptible to TB and that India, at least is no longer a poor country so perhaps they should be doing something themselves to ameliorate the nutrition status of its people!
