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 is derived from the Latin "in + oculus" (eye). Though "innoculation/innoculate" (with a double "nn" rather than a single "n") is sometimes seen, this is incorrect, possibly erroneously thought to be related to innocuous, which is derived from the Latin "in + nocuus" (not harmful). Inoculation originated as a method for the prevention of smallpox by deliberate introduction of material from smallpox pustules into the skin. This generally produced a less severe infection than naturally-acquired smallpox, but still induced immunity to it. This first method for smallpox prevention, smallpox inoculation, is now also known as variolation. Inoculation has ancient origins