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,
History of smallpox belief, the city instructed teams of physicians to vaccinate anyone living in inexpensive housing. In an effort to control the outbreak, the Boston Board of Health began voluntary vaccination programs. Individuals could receive free vaccines at their work places or at different stations set up throughout the city. By the end 1901, some 40,000 of the city’s residents had received a smallpox vaccine. However, despite the city's efforts, the epidemic continued to grow. In January 1902, a door-to-door vaccination program was initiated. Health officials were instructed to compel individuals to receive vaccination, pay a $5 fine, or be faced with