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
Mozart and smallpox reached European countries. Inoculation was not the same as the vaccination which later succeeded in eradicating the disease; rather, an inoculated person was treated with live smallpox virus, taken from pustules of the mildest variety of smallpox that could be found. Inoculation offered immunity to smallpox, but the procedure carried a definite risk that the inoculated person could die from smallpox as a result. Thus, many parents felt that they would rather do nothing, risking future smallpox arriving at random, rather than carry out a deliberate act that might well kill their children immediately. As Mozart biographer Ruth Halliwell points