A new national health concern involves an old childhood illness -- measles. The viral infection that causes a severe, itchy rash is back after being almost eradicated in America because a vaccine developed in the 1960s is required before pupils begin kindergarten. In recent years, however, a movement has spread among some parents who fear the vaccine could cause side effects or even autism.

Nineteen states let parents cite philosophical or personal beliefs, in addition to religious or medical exemptions, as their reason for not having a child immunized. Waivers are blamed for a California outbreak traced to Disneyland. More than 150 cases exist in 14 states, from the West Coast to New York and Pennsylvania. The number of patients is likely to grow.

Although measles occasionally can be fatal or cause brain damage, nothing that serious has happened yet. Still, alarm and anger surfaces. Editorial writers and columnists blasted Chris Christie, the Republican governor of New Jersey, for recently saying: "It's much more important, I think, what you think as a parent than what you think as a public official." On the Democratic side, possible presidential candidate Hillary Clinton tweeted last week: "The science is clear: The earth is round, the sky is blue and vaccines work. Let's protect all our kids." The measles vaccine is more than 99-percent effective in preventing the disease, according to the national Centers for Disease Control and Prevention. President Obama also is speaking out, saying on the Today show: "There is every reason to get vaccinated, but there aren't reasons to not."

Doctor says: "Which parent would want to put their kids through this?" -- Dr. David Samadi, New York City

Editorial says: "When individuals selfishly refuse to vaccinate their children, seeking a free ride on the rest of the herd, immunity breaks down and innocents are put at risk." – USA Today

Vaccine critic says: "My child is pure. It’s not my responsibility to be protecting their child." – Dr. Jack Wolfson, Arizona heart doctor