OPINION: What we've forgotten about the danger of childhood diseases

More than 100 people in 14 states were reported to have measles last month, with most cases linked to exposure to the disease at Disneyland from December 15 to December 20. President Obama urged parents to make sure their children are vaccinated. And yet three potential Republican candidates for the 2016 presidential election have suggested in recent days that parents should have a choice in whether children should be vaccinated.