Calmette's main scientific work – which was to bring him worldwide fame and permanently attach his name to the history of
medicine – was the development of a vaccine against
tuberculosis, which remains the world's deadliest infectious disease. The
German microbiologist
Robert Koch had discovered, in 1882, that its pathogenic agent was the tubercle
bacillus,
Mycobacterium tuberculosis, and Louis Pasteur became interested in it too. In 1906, a veterinarian and immunologist working at the Institut Pasteur de Lille,
Camille Guérin, established that immunity against tuberculosis was associated with the living tubercle bacilli in the blood. Using Pasteur's approach, Calmette investigated how
immunity would develop in response to attenuated bovine bacilli injected in animals. This preparation received the name of its two discoverers (
Bacillum Calmette-Guérin, or BCG, for short). Attenuation was achieved by repeatedly cultivating them in a
bile-containing substrate, based on a theory of
Norwegian researcher Kristian Feyer Andvord (1855–1934). From 1908 to 1921, Guérin and Calmette strived to produce less and less virulent strains of the bacillus, by transferring them to successive cultures. Finally, in 1921, they used BCG to successfully vaccinate newborn infants in the
Hôpital de la Charité in Paris. The vaccination program, however, suffered a serious setback in 1930 when 72 vaccinated children developed tuberculosis in
Lübeck, Germany, due to a contamination of some vaccine batches in Germany. Mass vaccination of children was reinstated in many countries after 1932, when new and safer production techniques were implemented. Notwithstanding, Calmette was deeply shaken by the event, dying one year later, in Paris. ==Impact on industrial brewing ==