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,
Paris under Napoleon Beauharnais, the mother of Napoleon III, who both survived; it killed the poet Jean François de Saint-Lambert, and writers Laharpe and Maréchal. Napoleon created a Health Council under the Prefect of Police to monitor the safety of the water supply, food products, and the environmental effects of new factories and workshops. The committee also made the first systematic surveys of health conditions in Paris neighborhoods, and provided the first widespread vaccinations against smallpox. Napoleon also made efforts to improve the health of the city, by building a canal to provide fresh water and by constructing sewers under the streets that