This book discusses the application of knowledge acquired in the previous material in this series to the huge task of combating infectious diseases and alleviating suffering, disability and premature death, that these diseases still inflict all over the world. It covers interventions to prevent, reduce the impact of, or treat infectious disease. Chemical interventions and the principles behind the use of pharmacotherapies and other chemicals are discussed including vaccination mechanisms, variations in efficacy and controversies. Public health strategies including an overview of the range of strategies required in different situations, illustrating some interventions in both developed and developing countries are covered.