More than 100 people have been diagnosed with the disease in the last month. At least 90 of the cases were believed to have begun when a person contagious with the disease visited Disneyland.
The measles vaccine has been commonplace since the mid-1960s. Prior to the 1960s, nearly 4 million Americans under age 15 contracted the disease annually, says the United States Centers for Disease Control. The CDC had considered measles in the U.S. eradicated in 2000.
But last year the CDC reported 54 people in the U.S. have reported being infected with measles in January and February alone.
While most people recover well, measles can lead to ear infection, pneumonia, seizures, brain damage, and death, says the CDC.
Nearly 95 percent of kindergartners nationwide were vaccinated against measles, according to the CDC. However, 48 states allow for exemptions for medical or religious reasons.
Mississippi and West Virginia, the two states that allow only medical exemptions to vaccination, have had no measles cases this year.
Virginia is among the states that allow for medical or religious exemptions.
In Fairfax County, students are required to have a long list of vaccinations, including measles, mumps, rubella (MMR), polio, Hepatitis B, tetanus and whooping cough, among others.
Students must show vaccination proof to enter kindergarten and again to enter sixth grade, unless they opt out for religious or medical reasons. There is also a small number of “conditionally enrolled” students whose records are in the process of being obtained.
In 2011, the medical journal Pediatrics said that one in 10 parents don’t vaccinate within a vaccine schedule recommended by the CDC. About 13 percent either delayed, skipped or made up their own vaccine schedule.
In Fairfax County, the majority follow the vaccination guidelines, said an FCPS spokesman. The Virginia Department of Health has a tool to break down immunization records by school.
Here is how Reston schools stack up with overall vaccinations, according to the Virginia Department of Health.