As of late August, there had been more than 1,200 cases of measles across 31 U.S. states this year. It's a dispiriting comeback for a disease that was declared eliminated in this country in 2000. If the disease has not stopped spreading by the time you read this, the U.S. will likely have lost this status. The illness has been cropping up mainly in pockets of unvaccinated people. Those who choose not to immunize their families are placing at risk not only themselves and their children but also others who cannot be vaccinated because they are too young or have medical issues.