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,
Smallpox noted that, in the 8-month voyage of the First Fleet and the following 14 months there were no reports of smallpox amongst the colonists and that as smallpox has an incubation period of 10–12 days it is unlikely it was present in the first fleet, it is now known that the likely source was bottles of smallpox virus possessed by First Fleet surgeons and there actually was a report of smallpox amongst the colonists – a seaman, Jefferies. There is circumstantial evidence that smallpox was deliberately introduced to Aboriginal population. During World War II, scientists from the United Kingdom, United