Cowpox to the mild form of smallpox and the observation that dairy farmers were immune from smallpox inspired the first smallpox vaccine, created and administered by English physician Edward Jenner. The word “vaccination,” coined by Jenner in 1796, is derived from the Latin root "vaccinus", meaning of or from the cow. Once vaccinated, a patient develops antibodies that make them immune to cowpox, but they also develop immunity to the smallpox virus, or "Variola virus". The cowpox vaccinations and later incarnations proved so successful that in 1980, the World Health Organization announced that smallpox was the first disease to be eradicated
1972 Yugoslav smallpox outbreak the disease was considered to be eradicated in Europe. The population of Yugoslavia had been regularly vaccinated against smallpox for 50 years, and the last case was reported in 1930. This was the major cause for the initial slow reaction by doctors, who did not promptly recognize the symptoms of the disease. In October 1970, an Afghan family went on pilgrimage from Afghanistan, where smallpox was endemic, to Mashhad in Iran, triggering a massive epidemic of smallpox in Iran that would last until September 1972. By late 1971, smallpox-infected devotees on pilgrimage had carried the smallpox from Iran into Syria