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.
BCG vaccine potentially more severe in those with poor immune function. It is not safe for use during pregnancy. The vaccine was originally developed from "Mycobacterium bovis" which is commonly found in cows. While it has been weakened, it is still live. The BCG vaccine was first used medically in 1921. It is on the World Health Organization's List of Essential Medicines, the most effective and safe medicines needed in a health system. Between 2011 and 2014 the wholesale price was $0.16 to $1.11 USD a dose in the developing world. In the United States it costs $100 to $200 USD. As