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 to back that idea up. There are also scholars on the other side who suggest that too much of a delay lessens the strengthening effect of inoculation. With this being said, it has been revealed that the effect of inoculation can still be significant weeks or even months after initial introduction or the treatment showing that it does produce somewhat long-lasting effects (Banas & Rains, 2010). Involvement is the final element of the inoculation process. Pfau, et al. (1997a) defined involvement as "the importance or salience of an attitude object for a receiver" and is “among the most important and