I generally don’t cover purely political issues on this blog, but the second Republican primary debate from last night ventured into the area of vaccines and autism. Donald Trump has said in the past that he thinks the current “epidemic” of autism is caused by vaccines. He was challenged on this position during the debate, and face palms ensued.

Orac, perhaps presciently, gave a good recap of Trump’s anti-vaccine nonsense just yesterday. In 2007 Trump said:

“When I was growing up, autism wasn’t really a factor,” Trump said. “And now all of a sudden, it’s an epidemic. Everybody has their theory. My theory, and I study it because I have young children, my theory is the shots. We’ve giving these massive injections at one time, and I really think it does something to the children.”

That is pretty much exactly what Trump said during the second debate, almost word-for-word. This demonstrates several things about Trump, in my opinion. First, he feels comfortable forming his own opinions, based on nothing but casual observation and anecdote, even on complex scientific issues, without adequate information. The fact that the scientific community has come to an opposite opinion does not even seem to give him pause. Finally, he has learned exactly nothing on this issue over the last 8 years – nothing. He has added no depth or nuance to his position, let alone correcting his factual errors.

This belies Trump’s claim that, even though he may not currently have a mastery of the complex issues facing the world, issues the next president will need to deal with, he will master them by the time he takes the oath of office. On this issue Trump seems content to shoot overconfidently from the hip, not only missing the target but hitting innocent bystanders. He then blows the smoke from his pistol and holsters it with a swagger.

Let’s deconstruct Trump’s position.

First he claims there is an autism epidemic, citing as reference his own casual observations. On this issue Trump is dead wrong. I have written extensively about the fact that there is no autism epidemic. The apparent rise in diagnoses is an artifact of increased surveillance, broadening the definition, and diagnostic substitution.

Most recently there was an epidemiological study that reviewed autism prevalence around the world, and they found:

In 2010 there were an estimated 52 million cases of ASDs, equating to a prevalence of 7.6 per 1000 or one in 132 persons. After accounting for methodological variations, there was no clear evidence of a change in prevalence for autistic disorder or other ASDs between 1990 and 2010. Worldwide, there was little regional variation in the prevalence of ASDs.

No increase in autism during the exact time period in which Trump claims there was an autism “explosion.”

What about the “massive injections?” Here I have not idea where Trump is getting his information. At various times he has referred to kids getting, “pumped with 10 and 20 shots at one time, with one injection that’s a giant injection.” At no time during the vaccine schedule are 10-20 shots given at once, individually or even if you count combination vaccines. It’s just not true. He also exaggerates the size of the needles and the amount of fluid injected, comparing them to “horse” vaccines.

The core of his claim is that vaccines are linked to autism. This, of course, is simply not true. There has been extensive research over the last 20 years showing no link between vaccines and autism. Further the research has shown that autism is largely genetic, and that the signs of autism begin before children get most of their vaccines. In fact a recent study finds that there are signs in the womb – before any vaccines.

The final component of Trump’s claims is that vaccines should be spread out, not given all at once. This is the “too many, too soon” meme that anti-vaxxers have been spreading. This has been studied also. The evidence clearly shows that delaying or spreading out the vaccines compared to the recommended schedule does not reduce the incidence of any adverse outcome, it may actually increase some adverse outcomes, and it increases the incidence of vaccine-preventable diseases.

Trump promises:

If I were President I would push for proper vaccinations but would not allow one time massive shots that a small child cannot take – AUTISM.

— Donald J. Trump (@realDonaldTrump) March 27, 2014

Trumps beliefs about vaccines and autism are completely wrong. There is no autism epidemic, vaccines are not linked to autism, and spreading out the vaccines is demonstrably a bad idea. Trump is promising that as president he will listen to his gut, and not to experts, even on a complex medical issue about which he has no expertise.

In my opinion, this type of overconfidence is perhaps the most dangerous trait for anyone with power to have.

Two of the Republican candidates are physicians, Rand Paul and Ben Carson. Carson was asked first what he thought of Trump’s opinions. To his credit he said that there is no link between vaccines and autism, although he stumbled around looking like he was desperately trying to look like he wasn’t criticizing Trump.

But then when Trump repeated the exact same nonsense I discuss above, Carson replied that he agrees that the vaccines are perhaps lumped together too much and could be spread out. This gave Trump the opportunity to say, “That is all that I’m saying,” and then give Carson a “good boy” pat on the shoulder.

The moderator then went to physician candidate #2, Rand Paul, for a “second opinion.” Paul, who is an extreme libertarian, predictably said that while he believes in vaccines, parents should have the choice. He then repeated the too many, too soon idea and agreed with spreading out the vaccines.

This was a disaster. Carson and Paul had an opportunity to sharply criticize Trump and expose him for the bloviating buffoon that he is, on a medical topic where they, as physicians, could credibly claim expertise and therefore have solid ground upon which to stand. It was a golden opportunity to stand up for science. They blew it. They gave Trump and out, in fact they supported him by echoing a key piece of his pseudoscience. Just stunning.

Conclusion

We live in a complex world in which the public and our leaders have to wrestle with complex challenges. Science is perhaps our most powerful tool for understanding the world, and knowing which interventions are likely to be effective.

We need to demand from our elected representatives that they:

– Have a basic civic scientific literacy.

– Will listen to and respect the legitimate expertise of experts who have spent their careers studying complex subjects.

– Will properly use the best science available to inform public policy

– Will not trump (pun intended) the consensus of scientific evidence and opinion with their own ideology, naive impressions, or anecdotal experience.

I think it’s pretty clear that Trump fails on every count.