http://en.wikipedia.org/wiki/MeaslesComplications
Complications with measles are relatively common, ranging from relatively mild and less serious diarrhea, to pneumonia and encephalitis (subacute sclerosing panencephalitis), corneal ulceration leading to corneal scarring.<3> Complications are usually more severe amongst adults who catch the virus.
The fatality rate from measles for otherwise healthy people in developed countries is 3 deaths per thousand cases.<4> In underdeveloped nations with high rates of malnutrition and poor healthcare, fatality rates have been as high as 28%.<4> In immunocompromised patients, the fatality rate is approximately 30 percent.<5>
Prevention and public health
In developed countries, most children are immunized against measles by the age of 18 months, generally as part of a three-part MMR vaccine (measles, mumps, and rubella). The vaccination is generally not given earlier than this because children younger than 18 months usually retain anti-measles immunoglobulins (antibodies) transmitted from the mother during pregnancy. A second dose is usually given to children between the ages of four and five, in order to increase rates of immunity. Vaccination rates have been high enough to make measles relatively uncommon.