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 theory opinion. These contexts include: politics (e.g., Pfau et al., 1990; see Compton & Ivanov, 2013, for a review), health campaigns (e.g., Pfau & VanBockern, 1994; see Compton, Jackson, & Dimmock, 2016, for a review), marketing (e.g., Compton & Pfau, 2004) and education (Compton, 2011), among others. (See Banas & Rains, 2010, for a meta-analysis, and Compton, 2013, for a narrative overview.) The inoculation process is analogous to the medical inoculation process from which it draws its name; the analogy served as the inaugural exemplar for how inoculation confers resistance. As McGuire (1961) initially explained, medical inoculation works by exposing the