The story is familiar now, but still unsettling. A respected scientific journal publishes a study suggesting that childhood vaccines might cause autism. The study cannot be replicated, and the journal’s own investigation later shows that the data itself is suspect. But it’s too late: the great vaccine panic had begun. Scientists know that one study does not prove a theory, but some members of the public do not, says Mark Gray, Ph.D., research associate for the Center for Applied Research in the Apostolate and a professor at Georgetown University: “It speaks to how we consume science and how it is produced. They go in slightly separate directions.” Here, Gray talks with Simon Cleveland, Faculty Director of Georgetown’s Bachelor of Arts in Liberal Studies program, about the ethical and public health questions this incident raises.