Chapter 5 explores the early spread of vaccination in continental Europe. If news of Jenner’s discovery quickly spread abroad, the delivery of vaccine in a viable state proved a major challenge. Diplomatic and medical networks explain its early arrival in Germany and Austria. From 1799, Dr De Carro made Vienna a major centre for the spread of the practice, with the samples sent to Lord Elgin in Istanbul seeding the practice in Greece. The British military build-up in the Mediterranean opened new channels for the dissemination of English cowpox. By vaccinating sailors aboard ship, Drs Marshall and Walker brought fresh vaccine to Gibraltar and Malta and Marshall established vaccination in Sicily and southern Italy early in 1801. Dr Sacco’s discovery of a local source of cowpox in cattle in Lombardy in late 1800 led to important trials and, over the following decade, an impressive vaccination programme in northern Italy. In the interstices of war in Europe, the practice developed as an international enterprise with several important new hubs.