The human fight against infectious diseases is ancient and ongoing. It started with variolation, probably in China in the 17th century and in the West at the beginning of the 18th century. Like most innovations it aroused a good deal of opposition. Improvements in this form of preventive medicine, first by Edward Jenner and then by Louis Pasteur, did not put a stop to these objections, some founded on reasonable arguments, others on simple opinion or religious or moral convictions. To these were added systematic resistance, pseudoscientific arguments, personal attacks, fallacious statements, claims of victimization of vaccine opponents, and simple slander.