In 1991, Philadelphia experienced a measles outbreak. I was in medical school in the city, and I remember how difficult it was to control. Children—some of whom had never been immunized—died. Babies received measles vaccines at 6 months of age and again at 12 months. Countless measles vaccines boosters were given. Living through a measles epidemic and seeing its grave consequences only confirmed the need to immunize against vaccine-preventable diseases.
There is a short radio piece on that time here.