Though measles was declared eliminated in the U.S. decades ago, outbreaks do still happen here, and in other places it’s much more common. Before vaccines were widely available, it killed an estimated 2.6 million people worldwide each year.
Research:

Robert Moses and the Shaping of New York, Part 1
41:59

SYMHC Classics: Eradication of Smallpox
43:25

Behind the Scenes Minis: Progressive Medicine
22:11