BCG vaccine fine powder. Sometimes the powder is sealed with vacuum in a glass ampoule. Such a glass ampoule has to be opened slowly to prevent the airflow from blowing out the powder. Then the powder has to be diluted with saline water before injecting. The history of BCG is tied to that of smallpox. Jean Antoine Villemin first recognized bovine tuberculosis in 1854 and transmitted it, and Robert Koch first distinguished "Mycobacterium bovis" from "Mycobacterium tuberculosis". Following the success of vaccination in preventing smallpox, established during the 18th century, scientists thought to find a corollary in tuberculosis by drawing a parallel
Inoculation theory strengthen their original attitudes. It uses a threat on initial beliefs to trigger a person's desire to fight against the threat, ultimately reinforcing their attitude. William McGuire set out to conduct research “on ways of inducing resistance to persuasion, under the impression that while much experimental work was being done on factors that increased persuasive effectiveness, little was being done on ways of producing resistance to persuasion” (McGuire, 1964, p. 192). McGuire was motivated to study inoculation and persuasion as a result of the aftermath of the Korean War. Nine US prisoners of war, when given the opportunity, elected to