The World Health Organization declared in 2000 that the United States had eliminated measles. But now the U.S. Centers for Disease Control is warning that status may be lost, largely because of stubborn outbreaks of the virus in New York. “We’re embarrassed. We’re chagrined,” CDC adviser Dr. William Schaffner told CNN. There have been more than two dozen outbreaks across the country, fueled by low vaccination rates, but the two in New York have lasted for nearly a year. Dr. Nancy Messonnier, director of the CDC’s National Center for Immunization and Respiratory Diseases, told CNN the development is frustrating because there’s a safe and effective vaccine.