BCG vaccine fine powder. Sometimes the powder is sealed with vacuum in a glass ampoule. Such a glass ampoule has to be opened slowly to prevent the airflow from blowing out the powder. Then the powder has to be diluted with saline water before injecting. The history of BCG is tied to that of smallpox. Jean Antoine Villemin first recognized bovine tuberculosis in 1854 and transmitted it, and Robert Koch first distinguished "Mycobacterium bovis" from "Mycobacterium tuberculosis". Following the success of vaccination in preventing smallpox, established during the 18th century, scientists thought to find a corollary in tuberculosis by drawing a parallel
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