Today, more than ever before, parents are concerned about the safety of vaccines. Fear of vaccines has been fueled by information provided on television programs, in newspaper and magazine articles, and on the Internet. Much of this information is based on opinions that are unsupported by scientific evidence. As a result, some parents are choosing to withhold, separate, or space out vaccines. The consequences of delaying vaccines have been predictable; recent outbreaks of diseases such as pertussis and measles have centered on communities where parents have chosen not to vaccinate their children.1,2 Doctors, scientists, and public health officials, alarmed by the trend, have tried to counter the flood of misinformation, but their voices have often been drowned out by the journalistic drumbeat of balance, representing both sides of a controversy even when only one side is supported by scientific evidence. With the book Do Vaccines Cause That?! A Guide for Evaluating Vaccine Safety Concerns , Martin Myers and Diego Pineda step into the fray.3 Myers is the director of … Address correspondence to Paul A. Offit, MD, Children's Hospital of Philadelphia, University of Pennsylvania School of Medicine, Division of Infectious Diseases, Vaccine Education Center, Abramson Research Building, Room 1202D, 34th Street and Civic Center Boulevard, Philadelphia, PA 19104. E-mail: offit{at}email.chop.edu