The ethical challenge of infection-inducing challenge experiments

Challenge experiments that induce infections in healthy volunteers are an i mportant method for initial efficacy testing of candidate vaccines and for study of the pathogenesis of infectious diseases. Although these studies ca n be conducted safely for selected infectious diseases that are either full y treatable or self-limiting, they raise significant ethical issues. An eth ical framework is offered for evaluating infection-inducing challenge exper iments, which focuses on the scientific and public health rationale for con ducting these studies, the risks that they pose and the ways in which these risks can be minimized, the symptoms experienced by healthy volunteers tha t may cause discomfort or distress, the exclusion of vulnerable research su bjects, the informed consent process, the payment of volunteers, and the us e of isolation of volunteers to prevent infection of others.