As any new parent knows, vaccines are a pain in the tuchus—and not just for the infant. A baby born in the U.S. today is supposed to get 20 shots by the age of two. Unsurprisingly, many parents put it off. What is surprising is why: in a 2011 survey by the Centers for Disease Control and Prevention, 82% of parents who didn’t vaccinate their children on schedule cited worries about side effects, like learning or behavioral problems.

So the CDC commissioned a big study to look at this question. Researchers gathered vaccination records and ran a wide range of tests on more than a thousand 7- to 10-year-olds. The scientists then searched for any sign that fully vaccinated kids had an elevated risk of cognitive deficits, tics, speech impediments, learning disability or issues with attention or executive function.

The results were clear: there was no measurable increase in risk for any of these conditions among children who got vaccinated on schedule. The study is in the journal Pharmacoepidemiology and Drug Safety. [Shahed Iqbal et al, Number of antigens in early childhood vaccines and neuropsychological outcomes at age 7–10 years]

This good news should ease some of the anxiety from those visits to the pediatrician—unless, of course, you’re the one getting stuck.

—Wayt Gibbs

[The above text is a transcript of this podcast.]