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,
To the Youth in Western Countries To the Youth in Western Countries On 29 November 2015, Ali Khamenei, the Supreme Leader of Iran, published an open letter addressed to the youth in western countries. It is the second letter of its kind, the first one having been published in January 2015. Both were distributed via his accounts on various social media, including Twitter, Facebook and Instagram, using the hashtag #CommonWorry. The second letter deals with Khamenei's views on the causes of recent terrorism. It was written in response to the November 2015 Paris attacks and other contemporary terrorist actions, such as the Metrojet Flight 9268 crash