A significant decrease in each vaccine-preventable disease has occurred since the introduction of the respective immunizations now included in the recommended childhood immunization schedule. The process through which a vaccine must travel from development to approval and implementation is complex. Hurdles include receiving approval from several advisory committees, government agencies, and professional organizations. At each step in the process, data regarding safety, immunogenicity, and efficacy are evaluated continuously and rigorously. Once a vaccine is approved by the Food and Drug Administration (FDA) and incorporated into the recommended childhood immunization schedule, continuing issues include those that deal with supply, safety, effectiveness, and financing. The logistics of development and implementation of pediatric vaccine recommendations and policies are reviewed.