Measles was first imported into the New World in the early 16th century by European colonists, often with devastating effects on native populations. Rubella importation followed and led to congenital rubella syndrome. It is estimated that during the following 5 centuries, more than 200 million people globally died of measles. Disease incidence fell rapidly after the availability of vaccines in the United States for measles in 1963 and rubella in 1969, and after the availability of a combined measles-rubella vaccine in 1971. As vaccination expanded into other countries of the Americas, the Pan American Health Organization established a goal to eliminate measles from the Western hemisphere by 2002 and rubella by 2010. By 2004, transmission had been interrupted in the United States. However, there has been concern that pockets of transmission persisted or that transmission could be reestablished if immunization coverage levels declined.
Grabowsky M. The Beginning of the End of Measles and Rubella. JAMA Pediatr. 2014;168(2):108-109. doi:10.1001/jamapediatrics.2013.4603