On Sept. 27, 2016, the Region of the Americas was the first in the world to have eliminated measles, a viral disease that can cause severe health problems, including pneumonia, brain swelling and even death. This achievement culminated a 22-year effort involving mass vaccination against measles, mumps and rubella throughout the Americas.

Measles was the fifth vaccine-preventable disease to be eliminated from the Americas, after the regional eradication of smallpox in 1971, poliomyelitis in 1994, and rubella and congenital rubella syndrome in 2015.