The Great Influenza (2004)

Barry's account of the 1918 flu pandemic is really two books, and both are worth having. The first is a history of how American medicine became a science, built around William Welch and the new Johns Hopkins medical school; the second is the pandemic itself, which killed tens of millions of people worldwide. The scientific background makes the human disaster easier to understand: you see what researchers knew, what they got wrong and why they could not stop it. Its weakness is a fondness for heroic figures, and some readers will want to skim the long institutional chapters to reach 1918. Read today, it is uncomfortably familiar.