In recent years diseases like whooping cough, measles and mumps, have made a comeback. The reason for these epidemics can be traced to a group whose vocal proponents insist, despite evidence to the contrary, that vaccines are poison. As a consequence, parents and caretakers are rejecting vaccines for themselves and their families. In Deadly Choices, infectious-disease expert Paul Offit takes a look behind the curtain of the anti-vaccine movement. What he finds is a reminder of the power of scientific knowledge, and the harm we risk if we ignore it.