The few cases of measles occurring since 2005 have been due to foreign travelers.
Measles kills approximately a million people worldwide each year, affecting mainly children under the age of 10. The virus can cause miscarriages in pregnant women and deadly encephalitis in one-tenth of those infected. Currently, the United States has been suffering outbreaks (April and August 2008) due to a decrease in vaccine coverage among school-aged children - 20% of measles patients in the United States are hospitalized because of the illness, 3 of every 1000 measles patients die. 90% of unimmunized individuals who are exposed to measles contract the respiratory disease.
Measles is prevented by the MMR (measles - mumps - rubella) vaccine given to young children between 12 and 15 months of age, with a follow-up dose 4 weeks later or before beginning school.
Parents have been concerned over misinformation (The original study by Wakefield that began the investigation has been found to be fraudulent with fabricated data) regarding the use of the preservative thimerosal, a mercury-based chemical, in the MMR vaccine. Scientific evidence supported by legal decisions have shown that there is no connection between the vaccine and autism, a developmental disorder diagnosed around the age of 2, the same age when the vaccine is given.