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
Smallpox noted that, in the 8-month voyage of the First Fleet and the following 14 months there were no reports of smallpox amongst the colonists and that as smallpox has an incubation period of 10–12 days it is unlikely it was present in the first fleet, it is now known that the likely source was bottles of smallpox virus possessed by First Fleet surgeons and there actually was a report of smallpox amongst the colonists – a seaman, Jefferies. There is circumstantial evidence that smallpox was deliberately introduced to Aboriginal population. During World War II, scientists from the United Kingdom, United