Measles Elimination in the United States

In 1962, immediately preceding the licensure of the first measles vaccines in the United States, when measles was a nearly universal disease, Alexander Langmuir described the medical importance of measles to the country and put forth the challenge of measles eradication 1. Although most patients recovered without permanent sequelae, the high number of cases each year made measles a significant cause of serious morbidity and mortality. Langmuir showed that 190% of Americans were infected with the measles virus by age 15 years 1. This equated to roughly 1 birth cohort (4 million people) infected with measles each year. Not all cases were reported to the public health system; from 1956 to 1960, an average of 542,000 cases were reported annually. By the late 1950s, even before the introduction of measles vaccine, measles-related deaths and case fatality rates in the United States had decreased markedly, presumably as a result of improvement in health care and nutrition. From 1956 to 1960, an average of 450 measles-related deaths were reported each year (∼1 death/ 1000 reported cases), compared with an average of 5300 measles-related deaths during 1912‐1916 (26 deaths/ 1000 reported cases) 2. Nevertheless, in the late 1950s, serious complications due to measles remained frequent and costly. As a result of measles virus infections, an average of 150,000 patients had respiratory complications and 4000 patients had encephalitis each year; the latter was associated with a high risk of neurological sequelae and death. These complications and others resulted in an estimated 48,000 persons with measles being hospitalized every year 3.