The Twentieth-Century was a dangerous time to be young. Before vaccines, there were a multitude of diseases that too often kept children from reaching even their teenage years.  From the throws of that environment, Dr. Maurice Hilleman would emerge to lead a revolution in vaccine innovation and save many millions of young lives each year. But after being forced to retire at the height of his productivity in 1985, Hilleman watched as one company after another began to abandon vaccine research.  When parents began choosing not to vaccinate their children in the 1990s the cruel irony became clear; Hilleman’s unprecedented successes had allowed us to forget just how devastating childhood diseases could be.