ABSTRACT
The tremendous benefits of immunization in reducing the morbidity and mortality of infectious diseases are well recognized, both from a public health perspective as well as from an individual perspective. Widespread use of vaccines in the past century has led to improved control of many infectious diseases including diphtheria, pertussis, and measles, and eradication or near eradication of diseases, i.e., smallpox and polio [1]. However, this public health triumph comes with the implicit understanding that effective health interventions such as immunizations are not completely free of risk. Vaccines are held to the highest standards of safety because they are usually given to healthy individuals (often children) to prevent an infectious disease to which they might be exposed in the future rather than treat an established disease or condition. Yet vaccines, like all pharmaceutical products, can have adverse effects ranging from transient common local reactions to rare but serious and irreversible events. Successful immunization strategies incorporate rigorous scientific assessments to ensure the safety of vaccines both preand postlicensure, and effectively communicate the benefits and risks to the public.
