The subtitle is a tipoff: like his earlier blast at the eugenicists (The Legacy of Malthus, 1976), Chase's dual history of immunology--the medical discoveries and the public-health reforms--would benefit from being half as long, half as repetitive, and considerably less pious. He is the first, however, to attempt to link the two strands. He provides good (if encyclopedic) chronological histories of, on the one hand, 19th-century British and American crusades for antisepsis or asepsis, child labor laws or sanitation measures; and, on the other hand, the accomplishments of Jenner, Pasteur, Koch, Ehrlich, Metchnikoff, Salk, Sabine, and many of their present-day successors. He is able to explain the scientifically knotty problems of immunology: why, for example, vaccines made from whole organisms have been largely replaced by the surface molecules or bacterial byproducts that can stimulate the production of immune cells and antibodies. The conscientious reader will understand why, in almost 200 years, only about a dozen useful vaccines against bacteria or viruses have been developed. At the same time, Chase has a lot to say about the responsibility of a democratic society to provide public-health and prevention services for all: from his earliest indictment of Malthus as the archenemy of vaccination (on grounds that smallpox was the ordained means of reducing the ranks of the poor) to his final judgment on the Reaganomic budget-cutting that threatens free immunization programs. A prospective audience exists, certainly, among public-health-oriented medical and biology students; but Chase might have had far more readers had he trimmed his text and toned down his righteousness.