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Delaying Childhood Vaccines Doesn't Improve Mental Development

A young boy watches while a registered nurse administers an immunization shot before he enters kindergarten in Washington, D.C. Tim Sloan/AFP/Getty Images hide caption

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Tim Sloan/AFP/Getty Images

A young boy watches while a registered nurse administers an immunization shot before he enters kindergarten in Washington, D.C.

Tim Sloan/AFP/Getty Images

It isn't easy holding down a screaming child while a nurse gives him four shots in a row. We know. And we've all been tempted to postpone those dreaded shots for various reasons.

But evidence continues to mount that the wrestling match in the pediatrician's office is worth it: New research that followed more than 1,000 children over the course of seven to 10 years shows that delaying the childhood vaccines doctors recommend does not improve their mental development.

In fact, the study showed that the kids who got their vaccines on time actually did slightly better on some speech and language tests than their peers whose parents delayed or declined vaccination (see Table 2).

"These data may reassure parents who are concerned that children receive too many vaccines too soon," the study says. It's the first long-term study of its kind.

For several years, parents have worried that kids' bodies — specifically their immune systems — are not up to the task of taking all those shots at once. As NPR's Joanne Silberner has pointed out, the Centers for Disease Control and Prevention recommends kids get vaccinated against 13 diseases before age 2.

That sounds like a lot, but experts say parents should be more concerned about exposing unvaccinated kids to serious diseases like whooping cough and meningitis.

"Our study shows that there is only a downside to delaying vaccines, and that is an increased susceptibility to potentially deadly infectious diseases," Dr. Michael J. Smith of the University of Louisville School of Medicine, who helped write the study, told U.S. News.

Other parents worry that exposure to the preservative thimerosal will cause autism — concerns that persist despite overwhelming evidence to the contrary.

On a side note, Britain just banned from the practice of medicine — for "ethical lapses" — the doctor responsible for drawing links between autism and vaccines.

The study of kids and vaccines appears in the June edition of the journal Pediatrics.