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 the French scientific mission of 1839–1841. The knowledge of inoculating oneself against smallpox seems to have been known to West Africans, more specifically the Akan. A slave named Onesimus explained the inoculation procedure to Cotton Mather during the 18th century; he reported to have gotten the knowledge from Africa. In January 1714 Philosophical Transactions of the Royal Society published an account of a letter John Woodward had received from Emmanuel Timonius in Constantinople. Smallpox inoculation was advocated as a proven method of curbing the severity of the disease. The practice was introduced to England by Lady Mary Wortley Montagu. Lady