Health officials warned eight would-be travelers thought to have measles that they could be placed on the Centers for Disease Control and Prevention’s Do Not Board list, prompting them to cancel their flights. Martin Cetron, director of the CDC’s Division of Global Migration and Quarantine, said the list’s “deterrent effect is huge.” The agency was alerted to the eight individuals by health officials in New York, California, Illinois, Texas, and Washington, the CDC told The Washington Post. Officials in Rockland County, New York, and New York City have warned several infected people against traveling. Rockland has had 238 measles cases since October, while NYC has reported 523 cases. The Do Not Board list was created in 2007 when an Atlanta man ignored health officials’ advice and flew to Europe for his wedding despite having contracted a drug-resistant form of tuberculosis.