Developed from a New York Times series -- not really in depth -- this is purely and simply enough for any reader a report of where this branch of science is and might be going. The tone is forward-looking and sanguine. Specifically the author reviews the Rh factor in fatal infant anemia; the immune response via antibodies; cancer where immunology is making a frontal assault (cf. Time's piece on Dr. Good who appears here briefly); transplants (marrow in particular); measles which can lead to a deadlier and more arcane illness; smallpox and some of the established successes -- diphtheria, tetanus, polio -- which have rendered these diseases obsolete; the slower viruses which include multiple sclerosis; and reactions (the sub-title's referral) which can extend to shock. An easily accessible resume.