BCG vaccine 400 per 100,000 in that higher risk context). The age of the person and the frequency with which BCG is given has always varied from country to country. BCG is prepared from a strain of the attenuated (virulence-reduced) live bovine tuberculosis bacillus, "Mycobacterium bovis", that has lost its ability to cause disease in humans. Because the living bacilli evolve to make the best use of available nutrients, they become less well-adapted to human blood and can no longer induce disease when introduced into a human host. Still, they are similar enough to their wild ancestors to provide some degree of
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