BCG vaccine extensively used even in countries where efficacy against pulmonary tuberculosis is negligible. A number of possible reasons for the variable efficacy of BCG in different countries have been proposed. None have been proven, some have been disproved, and none can explain the lack of efficacy in both low-TB burden countries (US) and high-TB burden countries (India). The reasons for variable efficacy have been discussed at length in a WHO document on BCG. BCG has protective effects against some non-tuberculosis mycobacteria. BCG has been one of the most successful immunotherapies. BCG vaccine has been the "standard of care for patients with
Inoculation theory the appropriate tools to combat the attack were more resistant than the control group. In this case, the simple act of forewarning of an attack was enough to resist the counterattitudinal persuasion. The second component, refutational preemption, is the cognitive part of the process. It is the ability to activate one's own argument for future defense and strengthen their existing attitudes through counterarguing (Pfau, 1997). Scholars have also explored whether other resistance processes might be at work, including affect. Refutational preemption provides specific content that receivers can employ to strengthen attitudes against subsequent change. This aids in the inoculation process