Virology in order to immunize others. In 1717 Lady Mary Wortley Montagu observed the practice in Istanbul and attempted to popularize it in Britain, but encountered considerable resistance. In 1796 Edward Jenner developed a much safer method, using cowpox to successfully immunize a young boy against smallpox, and this practice was widely adopted. Vaccinations against other viral diseases followed, including the successful rabies vaccination by Louis Pasteur in 1886. The nature of viruses however was not clear to these researchers. In 1892, the Russian biologist Dmitry Ivanovsky used a Chamberland filter to try to isolate the bacteria that caused tobacco mosaic
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