Pain-free? More kids skipping school vaccines

WILLIAMS: story tonight. Lisa , thanks.

BRIAN WILLIAMS, anchor: the parents that will not allow their children to be vaccinated because they are worried about unintended consequences of the vaccines. A new analysis finds that a growing number of parents in more than half the states in this country are opting out of getting shots for their kids. The problem with that is we have vaccines, of course, for a reason. The alternative can be disease, in some cases epidemics. That's why it's called public health . And so the choices of a few can affect a lot of people who have followed the rules, and that's why this is being watched so closely. Our report tonight from Dr. Nancy Snyderman .

We have new numbers to report tonight on an increasing trend: Five-year-old Ella and her little brother Ethan are healthy, happy and unvaccinated. Their mother, Lisa Morris , a practicing chiropractor from Buffalo , decided against all immunizations, an about-face from the way she was raised by her mother, a practicing nurse. Why the decision?

Dr. NANCY SNYDERMAN reporting: The thought that more vaccines is better, so the more the better, the more the healthier. And I really don't know if that's true.

Ms. LISA MORRIS: Increasingly, thousands of parents are making the same decisions as Lisa and veering away from the recommended immunizations. Now eight states report than more than one in 20 children has not been properly vaccinated. Just last year, California experienced an outbreak of whooping cough affecting 2100 children. Ten infants died. And Minnesota faced a cluster of measles infections last March. These outbreaks have health experts worried.

SNYDERMAN: Good girl!

Unidentified Woman: There's still a lot of confusion because many young parents have no knowledge of the diseases that we're trying to prevent.

Dr. WILLIAM SCHAFFNER (Vanderbilt University): Do you want a Band-Aid ? OK.

Offscreen Voice: Diseases like measles, mumps, polio, meningitis, chicken pox and hepatitis. Lisa is among a growing number of parents who are educated, middle class, white, and get much of their medical information from the Internet . But many experts say it's misinformation.

SNYDERMAN: I believe there is a moral and ethical responsibility to being vaccinated ourselves, have our children and grandchildren vaccinated.

Dr. SCHAFFNER: Still, Lisa is confident she's made the right choice for her children.

SNYDERMAN: Everyone is programmed that vaccines are so great.

Ms. MORRIS: But public officials counter that making a personal decision for your family may not necessarily be the best one for your community. As it stands right now, 90 percent of American children are vaccinated. And that threshold is very important because that means that communities are, in fact, protected. But the concern obviously, Brian , is if that number drops, the grandmother who's on chemotherapy, the aunt who may be struggling with rheumatoid arthritis, those are our vulnerable people. So that four-year-old may, in fact, be transmitting a disease that could have been prevented and, in fact, could make those people, our most vulnerable -- could mean a death sentence for them.

SNYDERMAN: All right, we'll keep covering this. Nancy Snyderman . Thank you, as always.

WILLIAMS: You bet.

SNYDERMAN: We turn now to Wall Street , where stocks bounced back big from the worst Thanksgiving

BRIAN WILLIAMS, anchor: