BCG vaccine screened for active tuberculosis. BCG is also contraindicated in certain people who have IL-12 receptor pathway defects. BCG is given as a single intradermal injection at the insertion of the deltoid. If BCG is accidentally given subcutaneously, then a local abscess may form (a "BCG-oma") that can sometimes ulcerate, and may require treatment with antibiotics immediately, otherwise without treatment it could spread the infection causing severe damage to vital organs. However, it is important to note an abscess is not always associated with incorrect administration, and it is one of the more common complications that can occur with the vaccination.
Inoculation considerable opposition arose to the introduction of inoculation, and it was banned by the Parlement. Voltaire, in his "Lettres Philosophiques", wrote a criticism of his countrymen for being opposed to inoculation and having so little regard for the welfare of their children, concluding that "had inoculation been practised in France it would have saved the lives of thousands.". Inoculation grew in popularity in Europe through the 18th century. Given the high prevalence and often severe consequences of smallpox in Europe in the 18th century (according to Voltaire, there was a 60% incidence of first infection, a 20% mortality rate, and