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 Inoculation theory Inoculation theory was developed by social psychologist William J. McGuire in 1961 to explain how attitudes and beliefs change, and more importantly, how to keep existing attitudes and beliefs consistent in the face of attempts to change them. Inoculation theory functions as a strategy to protect attitudes from change–to confer resistance to counter-attitudinal influences, whether such influences take the form of direct attacks or sustained pressures. The theory posits that weak counterarguments–arguments that are easily refuted–generate resistance within the receiver, enabling them to maintain their beliefs in the face of a future, stronger, attack. Following exposure to weak