The word conjures up apocalyptic images in the public imagination, visions of horrific diseases rapidly sweeping the globe and killing any with whom they come into contact. But such highly lethal illnesses almost never create pandemics, writes Peter C. Doherty. The reality, if deadly serious, is far subtler. InPandemics, Doherty, who won the Nobel Prize for his work on how the immune system recognizes virus-infected cells, offers an essential guide to one of the truly life-or-death issues of our age. Step by step, he examines the causes of pandemics, explains how they can be counteracted with vaccines and drugs, and outlines how we can better prepare for them in the future. The term "pandemic," Doherty notes, refers to a disease spreading rapidly over a wide geographical area, rather than to its severity. Especially lethal pathogens make their presence known quickly, and are usually quickly confined. Nevertheless, the rise of high-speed transportation networks and the globalization of trade and travel have radically accelerated the spread of diseases. One traveler from Africa arrived in New York in 1999 with the West Nile virus in his or her blood; one mosquito bite later, it was loose in the ecosystem. Doherty explains how the main threat of a pandemic comes from respiratory viruses, such as influenza and SARS, which disseminate with incredible speed through air travel. The climate disruptions of global warming, rising population density, and growing antibiotic resistance all complicate efforts to control pandemics. Yet, Doherty stresses, they can be fought effectively. Often simple health practices, especially in hospitals, can help enormously. And research into the animal reservoirs of pathogens, from SARS in bats to HIV in chimpanzees, can focus our prevention efforts. Calm, clear, concise, and, most of all, authoritative, Peter C. Doherty'sPandemicsrepresents one of the most critically important additions to theWhat Everyone Needs to Knowseries.