Vaccines face a paradox: without them, people die, and yet protesters seem to fear vaccines more than disease. This book reminds us how vital vaccines are, clarifies the issues surrounding them, and confronts rumor with fact. As COVID-19 has shown, there is an ethical component to their use, since they protect us not only individually but as a society. Science historian Patrick Zylberman is a Professor Emeritus of Public Health at the École des hautes études and co-founder of the Val-de-Grâce conference on emerging infectious diseases.