The human immune system is nothing short of remarkable: it helps our bodies ward off bacteria and viruses, heals wounds, and maintains the balance needed to keep us alive. The good news? Our immune systems are no longer threatened by the plagues and common diseases of the past. The bad news? Our bodies face an array of distinctively modern challenges; threats like fatigue, stress, and exposure to toxins, which place undue pressure on a system that typically keeps us healthy. Could the results of such stressors be weakened immunity and an explosion of autoimmune disorders?

In his new book, An Elegant Defense, bestselling author Matt Richtel explores this very question through the stories of four people — a cancer patient, an HIV patient, and two women with autoimmune diseases. Combining these human accounts with anecdotes, insight from leading researchers, and the latest scientific findings, Richtel describes how the body’s forces unite to ward off bacteria, parasites, and tumors. And on the flip side, he explains how sometimes the body’s defenses can become a threat and attack organs and other systems. Richtel investigates why: Is there a close connection between mental health and the immune system? What roles do diet and nutrition play in immunity? What might be weakening our immune systems? (Think antibacterial soaps, immune boosters, and other products marketed to “protect” us.)

With discussion about health and the immune system remaining in the spotlight as the COVID-19 pandemic rages onward, Richtel offers a particularly relevant look into the deepest riddles of human survival and suggests potential keys to improving wellness.

Matt Richtel is a Pulitzer Prize-winning New York Times reporter and bestselling nonfiction and mystery author. He lives in San Francisco with his wife, Meredith, a neurologist, and their two children. In his spare time, he plays tennis and piano and writes (not very good) songs.