Background

Documented cases of measles date back to at least the ninth century. The Centers for Disease Control and Prevention traces the history of measles along milestones in its discovery, identification as an infectious disease, and its effect on the U.S. population.

Measles vaccines have been available since 1963. The combined measles, mumps, and rubella vaccine has been available since the early 1970s. Widespread vaccination and improved sanitary conditions have drastically reduced disease rates in the U.S. and abroad. Globally, measles deaths have decreased by 84% in recent years, from 550,100 deaths in 2000 to 89,780 in 2016.¹ Yet measles is still common in many developing countries, particularly in Africa and Asia. An estimated 7 million people contracted measles in 2016.² The overwhelming majority (more than 90%) of measles deaths occur in countries with inadequate healthcare infrastructure.

Measles was thought to have been eliminated from the U.S. in 2000. However, outbreaks in other countries to which Americans often travel (e.g., England, France, Germany, India, Israel, the Philippines, and Vietnam) have increased the spread of measles in U.S. communities with unvaccinated people (compared to previous post-elimination years).³ There have been at least 50 U.S. measles cases reported each year between 2010 and 2019.⁴ Worker infections have also been reported, including among 29 healthcare workers infected between 2001 and 2014 as a result of occupational exposures in U.S. healthcare facilities.⁵