Bush was in the White House, Madonna was on the radio and the country was in the grips of its last major measles outbreak - until today. It was the worst outbreak the country had seen since the measles vaccine, which also targeted preventable illnesses mumps and rubella, was introduced in 1963. open image in gallery Measles is a nasty virus that can lead to life-threatening brain swelling in children who are unvaccinated. open image in gallery This map from the CDC shows measles cases across the U.S. so far this year. Many low-income families also did not have access to primary care physicians who could give children vaccines, Redlener explained.