It is true that vaccination has reduced measles and most other vaccine-preventable diseases to very low levels in the United States. However, measles is still very common—even at epidemic levels—in other parts of the world. Visitors to the U.S. and unvaccinated U.S. travelers returning from other countries can unknowingly bring (import) measles into the United States. The measles virus is very contagious and can live for up to two hours on a surface or in an airspace where an infected person coughed or sneezed. Nine out of 10 individuals who are not immune to the disease will become infected with measles should they come in contact with a person who is ill. Thus, even one case of measles can cause the disease to spread very quickly if many people are unvaccinated or not immune.
About one in five unvaccinated people in the United States who get measles is hospitalized. To protect your children, yourself, those who cannot medically be vaccinated, and others in the community, it is important to be vaccinated against measles. You may think your chance of getting measles is small, but the disease still exists and can still infect anyone who is not protected. Because some children are too young to be immunized, it's important that those around them are vaccinated to protect them. Individuals born before 1957 are presumed to be immune to measles.