Mozart and smallpox the imperial family were successful, and led to greater public acceptance for the procedure. Smallpox struck the Mozart family again in the next generation: Nannerl's eldest son Leopold and two of her stepchildren caught the disease during an outbreak in the Salzburg area in 1787. All three children survived. In 1796, the discovery of vaccination—the use of the related cowpox virus to immunize against smallpox—by Edward Jenner revolutionized the ability of medicine to deal with smallpox. Vaccination reached Vienna around 1800, when yet another local epidemic created impetus for its adoption. One of the doctors trained in the Vienna campaign,
Vaccination policy Somalia in 1977. Endemic measles, mumps and rubella have been eliminated through vaccination in Finland. The WHO has targeted polio for eradication by the year 2018. Rational individuals will attempt to minimize the risk of illness, and will seek vaccination for themselves or their children if they perceive a high threat of disease and a low risk to vaccination. However, if a vaccination program successfully reduces the disease threat, it may reduce the perceived risk of disease enough so that an individual's optimal strategy is to encourage everyone but their family to be vaccinated, or (more generally) to refuse vaccination