The Psychology of Vaccine FearI was reading the other day about the rise in the percentage of parents who opt-out of having their kids vaccinated. This was in California, so it may not apply to the entire country. But there is a disturbing uptick of parents — especially those who enroll their children in private schools — who don’t get their kids vaccinated.

Three times as many private versus public schools don’t make the grade. More than 15 percent of the private schools in California failed to reach a 90 percent immunization rate, compared with 5 percent in public schools. Ninety percent is what public health officials believe is the minimal rate needed in order to keep many of these childhood diseases at bay.

This rate has doubled in schools in California over the past decade, fueled largely by rumor and lies about vaccinations, their value to a society, and bad science that was trumped up over decades worth of previous research by respected institutions and researchers.

Why are some parents making decisions for their children based upon fear and bad science? Let’s find out.

First, let’s be clear that the vast majority of parents aren’t making these kinds of poor choices for their children. Most parents want what’s best for their kids, and that means keeping them healthy and safe from disease.

Parents cite a variety of reasons for not immunizing their children, among them: religious values, concerns the shots themselves could cause illness and a belief that allowing children to get sick helps them to build a stronger immune system.

The story also says “like many parents who refuse some or all immunization shots, [one mother] worries her children’s immune system could be overwhelmed by getting too many vaccines at once.” While that’s a common mantra among the vaccine deniers, there appears to be little evidence to support that a child could suffer from too many immunizations at once.Prevention, whose primary purpose is to ensure society’s stable health.

I also see another factor at work here… Something called confirmation bias (or myside bias). It’s the psychological tendency of people to favor information that confirms their own personal, pre-existing beliefs or hypotheses about something. We all do it, and we do it all the time.

With the information so readily available online today, it’s not hard to conduct some quick research and find a community of people who agree with you, no matter what the subject or your opinion on it. I’m not sure vaccine deniers would’ve ever gotten the time of day two decades ago, pre-Internet era. But because they all found each other online so more readily, it let them spread their misinformation and fears in a way that was self-reinforcing.

That’s both the power and the predicament of the Internet — it spreads ideas fast, no matter how good or bad those ideas are.

We’ve been giving vaccines to children for decades now, and the overwhelming, vast majority of the scientific data show this has resulted in a positive gain for society as a whole. It’s unfortunate some parents don’t understand these benefits, not just for society, but for their child’s own safety and well-being too.


Read the full story: Private school vaccine opt-outs rise


  1. Do Children Get Too Many Immunizations?
    The Answer is No.