'It's as commonplace as it is true to say that infectious disease knows no borders. In War Against Smallpox, Michael Bennett offers us something immeasurably more intriguing: the border crossing of vaccination. Bennett follows this strange procedure's rapid-fire travels from London to Spain, India, the Cape, the New World, China and beyond. And as if that intercontinental story is not fascinating enough, it all took place either side of 1800, as the global Revolutionary and Napoleonic wars wrenched the world into a new century. A major new global history. The world connected arm-to-arm.' Alison Bashford, University of New South Wales