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 smallpox, and when the Narvaez expedition stopped at Cozumel and Veracruz in 1520, the disease gained a foothold in the region. The introduction of smallpox among the Aztecs has been attributed to an African slave (by the name of Francisco Eguía, according to one account) but this has been disputed. From May to September, smallpox spread slowly to Tepeaca and Tlaxcala, and to Tenochtitlán by the fall of 1520. At this time, Cortes was returning to conquer the city after being thrown out on the Noche Triste. Cortes names only one indigenous leader who died of smallpox, Maxixcatzin. However, Cuitláhuac