More than 100 people in the United States have become infected with the measles virus since December, prompting the White House on Friday to urge parents to get their children vaccinated.
Measles is highly contagious. Symptoms include a blotchy rash, fever and runny nose. No deaths from the airborne virus have been reported in the current outbreak.
White House spokesman Josh Earnest told reporters that the science of vaccinations "is really clear." He said vaccination decisions should be made by parents, who should heed public health recommendations and inoculate their children.
More than 90 of the cases of the highly infectious virus have been reported in California, where state health officials have epistemologically linked nearly 60 cases to the Disneyland theme park. At least six other states have also reported measles cases believed linked to Disneyland.
The Centers for Disease Control and Prevention says the measles-mumps-rubella vaccine is 97 percent effective in preventing measles.
A significant number of American parents — including many in California — are choosing not to vaccinate their children. They cite concerns about introducing so-called "poisons" into their children's bodies and side effects, including autism.
But there is no link between autism and the vaccine, said Dr. Martha Rivera, a pediatric infectious-disease specialist in Los Angeles. She said that risk had been disproven.