Let’s get one thing out of the way first, shall we?  Vaccines don’t cause autism.  If you’ve got a kid with a standard operating immune system, you oughta get that sucker vaccinated.  If you yourself have a standard operating immune system, and you’re considering living in a place where certain diseases that you aren’t immune to are prevalent, you oughta get yourself vaccinated.

But, okay, now that we’ve stated that much, there is an essay about vaccines and autism that I’ve been meaning to write.  Prompted, at the moment, by my turn in the queue for Eula Biss’s On Vaccination finally arriving.  Biss writes, with a lack of emphasis that I assume is ironic, though I am of course only a quarter of the way through her book at the time of this writing and so cannot know for certain, “Even so, the evidence reviewed by the committee ‘favors rejection’ of the theory that the MMR vaccine causes autism.”

Sure.  Let’s reject that theory.  There’s no evidence that vaccines cause autism; a scientist might use the word “hypothesis” to describe the idea that one might, but never “theory,” not given the data we have (by way of contrast, evolution is a theory.  Gravity is a theory; the next thing you drop, unless you’re on the space station, is probably gonna fall).  The conjecture that vaccines cause autism is a hypothesis, one that’s been tested and rejected.  Unless we accumulate a lot of new data that’s very dissimilar from the data we have now, rejected is how that hypothesis will stay.

And yet.  I wanted to write an essay about my favorite contemporary model for the cause of autism, and the idea that vaccination (or “mock vaccination,” actually, in which a child undergoes the ritual of vaccination but nothing is injected) might trigger the onset of autism.  This would happen only in children who were more or less guaranteed to have autism, but I can envision a compelling narrative in which the parents of many such children would all be able to point to an incidence of vaccination as the triggering moment.

There are, you may have noticed, many theories about what causes autism.  There’s the hippocampal under-pruning hypothesis; people with autism might have too many neural connections, trigger too many memories when it’s time to make decisions!  And of course there is also the over-pruning hypothesis; yup, the exact opposite idea has been proposed as the cause of autism, too!  It’s been proposed that autism results in underactivation of the fusiform gyrus, which is a part of the brain associated with processing faces and emotions.  And, yes, it’s been proposed that autism results in overactivation of the fusiform gyrus in emotional contexts, as though it’s hard to make eye contact, process emotions, etc., because they are perceived too strongly, not too weakly.  It’s been proposed that the condition is akin to a defensive response to stress, or that it’s linked to a deficit of oxytocin (the “cuddle molecule,” which K is planning to get a tattoo of once she’s done nursing), or that there are insufficient GABA-mediated inhibitory signals.

In short, many proposals, and nobody knows what’s correct.

Honestly, we don’t even how many people have autism.  You could read the CDC report and say, ah, 1 in 68 children have an autism spectrum disorder, but there are clear peculiarities in their numbers.  For instance, the huge increase relative to prior reports.  For instance, massive regional disparities; should we believe that autism is 4-fold more common in New Jersey than Alabama, or is there a difference in diagnostic capabilities?  And, as a point of contention near and dear to my own heart, the possibility that autistic children learn to mask their own condition.  If you asked K, for instance, she’d tell you that I have a mild autism spectrum disorder, but I’ve never been diagnosed.

And there are many proposed cures for autism.  Exogenous oxytocin (would hugs work instead, to promote endogenous oxytocin?); suramin, which reduces stress response (this hasn’t been proposed as a cure for humans, because the compound is toxic, but it seems to ameliorate autism-like symptoms in a mouse model); behavioral therapies …

… and my nomination for the all-time absolute WORST proposed cure, daily injection of massive doses of LSD. (This was first tested in humans, orphaned children, primarily, and was sometimes coupled with electroshock therapy.  But I should point out that our definition of the word “autism” has evolved somewhat in the time since these experiments were performed; if we go by modern usage, I think a more accurate description of these children would be “surly” rather than “autistic.” Still, reason enough to give them daily LSD. For months.)

All of which I’m mentioning so that you know to take everything I say about a possible “link” between autism and the practice of vaccination with a hefty dose of salt.  Clearly, nobody knows what’s up.

So, with all our caveats carefully stipulated, let’s get to it!  My current favorite model for the cause of autism, and how that might also relate to vaccines!

(Do I need to mention, here, that my use of the word model, singular, is somewhat silly since it seems very likely that there are multiple causes, perhaps multiple brain states that all get referred to as “autism” but which have differing neurological mechanisms?  I’m not sure.  I’ll mention it coyly, like this, in a parenthetical aside… that’s a good halfway approach, right?)

The model: maybe certain babies get too stressed out during birth, and that triggers autism (there is a nice summary of this model on the Simons Foundation Autism Research Initiative website).

A fetus’s brain activity is supposed to be suppressed during delivery, a process mediated by K’s favorite molecule. But something might be awry in autism, causing the suppression of brain activity to fail.  Seems there are suspicious clues speckled throughout the literature, like the fact that diazepam (Valium) often excites people with autism instead of calming them.  Indeed, my sister and I took an overnight bus ride through the mountains when I visited her in Ecuador (she was there for a three-year stint in the Peace Corps before medical school), and one of her friends lent us some Valiums.  My sister slept soundly.  I spent twelve hours chittering and jabbing her in the side with my elbow.

And, yeah, birth seems like it’d be incredibly traumatic… definitely seems like a good thing for babies’ brains to be conked.  Why not imagine that someone would be constantly musing “The horror, the horror” if there was any trace of memory about that whole ordeal?  There’s an increased percentage chance of autism after birth complications, though it’s difficult for me to say what types of delivery a baby would consider most stressful (like, would a baby think that a Cesarean delivery was easier?  Dunno, but Cesarean delivery is correlated with higher autism incidence, not lower like you might predict if your only working model were this highly speculative one I’m expounding upon).

In rodent models where pretreatment (either genetic or chemical) of fetuses tends to produce animals with some of the social disorders considered to be hallmarks of autism, it seems you can reduce the chance of producing an autistic-like animal by giving the birthing mothers a drug that stills the mind of the fetus.  Conk the baby chemically, it won’t remember its own birth, it grows into a neurotypical adult.

Within this framework, it seems possible that any episodes involving extreme stress could trigger autism onset in highly-susceptible individuals.  Vaccination, typically involving a shot, is stressful for some children.  So, there you go.  If you want to believe that there is *any* correlation between vaccination and autism beyond a coincidence in timing (i.e. when it’s first possible to diagnose autism and the standard vaccination schedule) this speculative hypothesis is the best I can come up with.  And it suggests that even if you believe there’s a link between autism and vaccination, there’s a strategy you could employ other than refusing vaccination, which endangers your own child and others.  You can simply make vaccination not stressful.

It’s not that hard, actually.  Yes, your kid is getting jabbed with a needle.  And it hurts, a little bit.  Not that much.  About as much as a hard pinch, which is crummy, and makes most kids cry, but easily fixable.  I’d say N has cried on average for about three seconds with each of her vaccinations, then we cuddle her some, she nurses, she’s happy again.  Part of why this works so well is that K stays calm and placid and cheerful throughout (I wish I could say the same about myself, but I have that thing where my blood pressure drops and I feel faint around needles.  K doesn’t; she performed thousands of injections on frogs during her doctorate and that experience washed away her needlephobia for good).  And our pediatrician is great.  And we sing, before, during, and after shots.

In summary… vaccinate your kids, kids.

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p.s. Was this all too chipper?  I do want people to be vaccinated against preventable diseases.  But, here, let me throw in a brief passage that I had to cut from an early draft of my novel to show that I understand why people are afraid of doctors; obviously bad things have been done.  Bad enough that any reasonable human would feel distrustful.  It’s just that, as regards contemporary pediatric vaccination, I don’t think the mistrust needs to be acted upon.  But, here you go, a little bit of horror to mitigate the preceding essay’s good cheer.

In early vaccine trials, orphaned children drank the pureed spinal chords of smallpox-infected monkeys.  Doctors put it in their milk.  The initial vaccination attempts failed: the virus was “insufficiently inactivated.”  Some of the children got sick.  Some were crippled for life.

Of course, they were living in an orphanage.  Not the most sanitary of conditions: some number of them were going to get sick anyway.  And for that study, the intent was therapeutic.  The drink might have been a vaccine.  Much more respectful toward what might’ve been the children’s wishes than, say, the hepatitis studies, in which orphans were deliberately infected so that attending doctors could track progression of the disease.  In that study, they were fed a slurry of pooled feces from other already-sick children.  Also in their milk, although for that study the noxious agent was blended into chocolate milk.  Probably seemed like a special treat.