The days when vaccines were something one received during childhood and just maybe again if visiting an undeveloped country are over. Terrorism and its accompanying threats have brought us anthrax vaccines and smallpox vaccines so far. New and dangerous public health threats are posed by West Nile Virus, SARS and AIDS not to mention exotic new types of flu viruses blowing in every year. These threats pose nontrivial threats to a weak public health system in America. Who for example, is to receive the vaccines if the supplies are limited or expensive: the rich, the military, the elderly, government workers, children? This volume brings together diverse studies of a new set of problems in America.