Vaccination policies and programs: the federal government's role in making the system work.

Government agencies play a key role, from preclinical development to postlicensure monitoring, in making vaccinations one of the leading public health interventions. Important steps in this process include development and testing of vaccine antigens, evaluation of clinical and manufacturing data leading to licensure, formulation of recommendations, vaccine purchase, defining strategies to improve coverage, compensation of those injured by vaccine adverse reactions, and monitoring vaccine impact and safety. Using examples of newly recommended vaccines, this article describes the infrastructure that underlies a safe and effective program and highlights some of the opportunities and threats likely to impact the system in coming years.