On its own, the topic of childhood immunization is controversial enough to fill an entire library with books on the subject. Since this book only has space for a single chapter, it will focus on the common misconceptions and fears about vaccines. An overwhelming abundance of vaccine opponents are always working hard to abolish childhood immunization. They tend to be more vocal and thereby to garner more media coverage than people who support the need for immunization. There is always a need for more authoritative medical sources to discredit the myths associated with the common medical procedure.