A groundbreaking exploration of the human immune system—the key to our health and longevity—from the Pulitzer Prize-winning New York Times journalist and acclaimed author of A Deadly Wandering. A cancer patient risen from the grave. An HIV patient considered a medical marvel. Two “invisible” women suffering the frustration and pain of autoimmunity. Matt Richtel uses the stories of these four people to tell the incredible story of the human immune system. In this vivid narrative, Richtel builds on his acclaimed stories on immunotherapy in the New York Times, combining the latest science with interviews and engaging anecdotes from the world’s leading researchers to reveal how the body marshals its forces to fight bacteria, viruses, parasites, and tumors. He also explains how, sometimes, this wondrous system that is our first line of defense can become a threat, attacking our organs and other systems. While modern life has freed us from many of the diseases that plagued humans in the past, it also puts unprecedented stress on the very system that keeps us healthy. The result has been an explosion of autoimmune disorders. Providing a clear look at the forces that drive survival and the body’s evolutionary history, Richtel details how immunologists are advancing medical breakthroughs; illuminates the close connection between the immune system and mental health, beauty, and weight; examines the latest findings about diet and nutrition on immunity; and offers us a glimpse of a future in which we lead longer, more comfortable lives. He also warns that we are weakening the system that protects us: rather than trusting the bodies’ natural defenses, many people turn to antibacterial soaps, immune boosters, and other products, resulting in the development of dangerous drug-resistant microbes that threaten health. An Elegant Defense is the first work of popular science to look at this vital human system that is as complex and intricate as the brain yet remains widely misunderstood. Joining the ranks of The Emperor of All Maladies and I Contain Multitudes, An Elegant Defense is an exhilarating and wondrous exploration of the immune system that transforms our knowledge of the human body and offers advice to help improve wellness.