Viewpoint: Yes, a properly run voluntary system could produce higher vaccination rates while also protecting parents' rights.

Viewpoint: No, mandatory vaccinations have greatly reduced the incidence of many diseases and should be maintained.

Controversies over vaccination are not a new phenomenon. Learned debates about the safety, efficacy, morality, and even theological status of vaccination have raged since eighteenth-century physicians began to investigate ancient folk practices meant to minimize the danger of smallpox. Analyzing the risks and benefits of immunization, however, requires sophisticated statistical approaches to general mortality rates, case fatality rates for specific diseases, and studies of the safety and efficacy of various vaccines.

Until the nineteenth century, reported mortality rates were generally very crude estimates, but attempts to provide more accurate measurements of vital statistics through the analysis of...