Vaccination has been cited as the most effective method of preventing the spread of infectious disease, and it has been credited with the eradication of such horrendous and potentially lethal illnesses as smallpox and polio. However, in recent years, growing numbers of parents have come to question the wisdom of vaccination, expressing fears over potential side effects on children. This informative text, augmented by in-depth sidebars, annotated quotes from medical experts, detailed graphs, and full-color photographs, explores the history of vaccines and provides a clearer understanding of the debate over the safety and efficacy of immunization programs.