Vaccination disease people tried to prevent by inoculation and was the first disease for which a vaccine was produced. The smallpox vaccine was invented in 1796 by English physician Edward Jenner and although at least six people had used the same principles years earlier he was the first to publish evidence that it was effective and to provide advice on its production. Louis Pasteur furthered the concept through his work in microbiology. The immunization was called "vaccination" because it was derived from a virus affecting cows ( 'cow'). Smallpox was a contagious and deadly disease, causing the deaths of 20–60% of
1837 Great Plains smallpox epidemic Early vaccination efforts by the Hudson's Bay Company were sporadic and unorganized during its monopoly period. Although the HBC recognized the potential of vaccination, understanding that more people ment more fur for them, there was no systematic vaccination program in place until the epidemic was well underway. Some vaccines were sent to trading posts early in the 19th Century but were left to collect dust. The smallpox infection spiked in 1780s, as persisted up to the 1837 epidemic. In what is now Canada, fur trade strengthened communities such as the Mushego Cree, Anishinabe, and Ottawa. The Mandan tribe had previously