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
History of smallpox in Mexico 1799. Viceroy Miguel José de Azanza, ordered an article written on 14 November 1799 about the benefits resulting from the inoculation in the 1790s epidemic and distributed to the population. In 1803, Spanish doctor Francisco Javier Balmis started a vaccination program against smallpox in New Spain, better known as Balmis Expedition, which reduced the severity and mortality in the epidemics that followed. Before Balmis, Dr José María Arboleyda started a vaccination campaign in 1801 but this was not successful. There was another important outbreak in 1814 which started in Veracruz and extended to Mexico City, Tlaxcala and Hidalgo. This epidemic