Young adults are driving vaccine skepticism in the U.S.

Who are the vaccine skeptics? 

On the heels of the Disneyland vaccine outbreak, that's what everyone wants to know. As with just about every other major issue facing the country, the temptation is to divide it along familiar left/right political divides. It may seem natural that Republicans, who tend to be skeptical of mandates and government intrusions, would be most opposed to vaccination policies. Or that Democrats, distrustful of big businesses like pharmaceutical companies, would harbor the most skepticism.

Measles Rash

But as it turns out, we're asking the wrong question. Public opinion polling shows that vaccination attitudes don't differ much by party affiliation. Or by income, or even education. But there is one important demographic factor: age.

Millennials -- 18 to 29-year-olds -- are about twice as likely as senior citizens (65+) to say that parents should decide whether their kids get vaccinated, rather than having it mandated by law. Republicans and independents are more likely to say this than Democrats, but here the split is not as stark.

More strikingly, 21 percent of millennials say it's likely that early childhood vaccinations are linked to autism, compared to only 3 percent of those aged 65+. There's little variation by political party on this question.

The Pew Research Center, which polled the first question, posits that "One possible reason that older groups might be more supportive of mandatory vaccinations is that many among them remember when diseases like measles were common." Having come of age in an era when measles was declared eradicated, millennials have no generational memory of time when hundreds of thousands of Americans were stricken with the disease each year. Not to mention polio, or smallpox.

Vaccines are partially a victim of their own success. They've done such a great job of wiping out deadly diseases that it's easy to become complacent. Largely liberated from having to worry about measles outbreaks, or tetanus, or polio, we're able to fret over whether vaccinations comport with an "all-natural" lifestyle. But we've forgotten that the incredible success of vaccination programs is what afforded us that luxury to begin with.

It may take more California-style outbreaks to jolt our memory.

Christopher Ingraham, 

Reporter — Washington, D.C.  Washington Post