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 (1995) posited that the use of inoculation strategies for these types of campaigns should be utilized to enhance the corporations' credibility and aide in maintaining the existing consumer attitude. This strategy should not be used to change consumer attitudes. Based on the analysis of previous research Burgoon et al. concluded issue/advocacy advertising is most effective for reinforcing support and avoid potential slippage in the attitudes of supporters. Based on previous publications they looked to test three hypotheses. The first was that issue/advocacy advertisements work to inoculate against counterattitudinal attacks. Next, issue/advocacy advertisements work to protect the source credibility. Lastly, conservatives