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 spreading inoculation through talk with others on issues that involve negative cognitions and affect. In previous research, the assumption that talk was subvocal (existing only intrapersonally) was prevalent, without concern for the impact of vocal talk with other individuals. Ivanov, et al. (2012) deems vocal talk important to the incubation process. Their study concluded that individuals who receive an inoculation message that contains threat will talk to others about the message and talk more frequently than individuals who do not receive an inoculation message. Additionally, the act of postinoculation talk bolsters their attitudes and increases resistance to the message as