Johnathan, type 1 from Louisiana, asks: Do tetanus shots cause blood sugars to spike or fluctuate?

Wil@Ask D’Mine answers: From all the research I could find, they don’t seem to. Which is odd, because the most common side effect of tetanus shots is pain at the injection site. In fact, the Centers for Disease Control and Prevention (CDC) says as many as two-thirds of all adults will experience pain, which can apparently last several days. And, as we all know, pain tends to raise blood sugar, at least for a time.

Darn. My arm is starting to throb just writing about it.

On top of that, about 1 percent of people develop a fever following the tetanus immunization, although no one is really sure why. It may be a productive part of the immune process, or it may simply be a side effect. Either way, any fever tends to raise blood sugar. Now, granted, that’s a small percentage of people, but given that everyone in the nation is supposed to get a tetanus shot every 10 years, that’s still a heck of a lot of people. Millions each year. So why aren’t more people whining about elevated BGs (blood glucose levels) following tetanus boosters?

Thanks to mail-order mice, I think I might have an answer to that. But first, a word from our sponsor: Lock jaw.

“Lock jaw” is the colloquial name for tetanus, because full-blown tetanus affects the nerves and causes severe (and painful) muscle contractions — particularly in the jaw and neck. How severe? Like, choke off your ability to breathe, severe.

Tetanus is caused by the bacteria Clostridium tetani, which is somewhat unique among bacteria. It is not communicable. In other words, you can’t catch it from someone else. Instead, it gets into your body through breaks in the skin in spore form, the dormant stage of the bacteria. You can think of the spores sorta like seeds: They can last pretty much forever, but just water them and Boom! you have a plant. Only in this case, the water is your blood and the plant is a disease.

Oh, and one other weird thing about Clostridium tetani: Our bodies don’t develop immunity from exposure, like they do with many other pathogens. Since tetanus is as likely to kill you as not if you get it, the best policy is to avoid getting it in the first place. And the only way to do that is to get vaccinated against it, and get a booster shot — some say every decade, others every three decades — to keep the original shot working.

Thanks to the vaccine, tetanus is actually quite rare. The CDC reports an average of only 30 cases per year, which is remarkable, given that tetanus spores are described by scientists as “ubiquitous” in the environment. That means the little buggers are everywhere! Of course, most of those 30 cases each year are in unvaccinated people.

Still, that said, apparently, we D-folks are three times more likely to contract tetanus than sugar-normals, and nearly twice as likely to die from it. And to make matters worse, fragile D-skin is more likely to let those darn spores in without a specific tetanus risk injury.

Now before we get to the mice, I need to talk about the rabbits. Apparently, some researchers in Lagos injected a bunch of rabbits with “purified tetanus toxin” and noted (before their poor little jaws locked shut) that the blood glucose of the rabbits went up, and kept going up the sicker they got.

The researchers concluded that the tetanus was actually toxic to the beta cells in the pancreas, reducing insulin production. OK, so now we know that full-blown tetanus (or being injected with purified tetanus toxin by a Nigerian researcher) will raise your blood sugar. But what about the tetanus vaccine? As it’s an inactive (i.e., dead) vax, you wouldn’t expect the vaccine to act on the body the way an active pathogen does.

And that’s what we’re really after here: to understand not what tetanus does, but what the tetanus shot does. And to understand that, let me introduce you to the mail-order mice.

For background, as I’m sure you know, there’s a small (but disproportionately vocal) community of anti-vaccination folks who blame vaxes for all manner of childhood illnesses. There’s no reliable science to back these beliefs up, and these same people have obviously never compared childhood mortality statistics from the pre-immunization period to today’s mortality rate. But of course it’s important to keep an open mind. Accordingly, French researcher Guillaume Ravel, PhD, and a group of his colleagues, went online and ordered themselves a bunch of mice.

Not just any mice, but a box of autoimmune diabetes prone non-obese (NOD) mice. These are genetically de-engineered critters that are ticking T1D time bombs. They’re used to study things that might cause diabetes, and interventions that might someday stop it. (I feel bad for the rabbits. I have mixed feelings about the mice.)

Anyway, as childhood immunizations had been implicated in causing, among other things, type 1 diabetes, Ravel figured he’d inject some diabetes-prone mice with a couple of different childhood immunizations and see what happened.

Both the controls and the immunized mice got diabetes at the same rate. In fact, the immunized mice fared slightly better, but not to a level of statistical significance.

So there was no evidence that the immunizations were either causing diabetes, or even triggering it in the already genetically pre-disposed mice. But in an incidental finding, the blood glucose levels of mice immunized with DTaP-IPV (engineered to protect against tetanus, along with diphtheria, whooping cough, and polio) were “significantly reduced” compared to the control mice, and NOD mice treated with a second immunization formula that also contained tetanus vax were also lower, although not as dramatically so.

Now that’s interesting.

This research led me to wonder: Even though the pain of the injection — and the fever in some people — should raise blood glucose, could there be something about the vaccine itself that lowers BGs? In people with diabetes, could it be a wash? Could the raising and lowering effects cancel each other out, causing our sugar to remain flat?

With the added benefit that our jaws don’t lock?

Wil Dubois lives with type 1 diabetes and is the author of five books on the illness, including “Taming The Tiger” and “Beyond Fingersticks.” He spent many years helping treat patients at a rural medical center in New Mexico. An aviation enthusiast, Wil lives in Las Vegas, NM, with his wife and son, and one too many cats.