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 reassures viewers that their opinion is still right and that Macs are in fact better than PCs. The inoculation theory in these ads keep Mac users coming back for Apple products and may even have them coming back sooner for the bigger and better products that Apple is releasing. That last part is especially important in a field like technology because it is continually changing and something new is always being pushed out onto the shelves. An example of inoculation theory usage in politics are present in studies indicating that it is possible to inoculate political supporters of a candidate