Welcome back to Microbial Mondays after the summer break! Since school is now under way, and with school comes cold and flu season, we're kicking off the new academic year with a very applied topic: vaccination.
This post was kicked off by a question from a friend who believed that it was a good idea to vaccinate, but couldn't quite find a way to express it. With this post, I hope to tackle some of the common misconceptions about vaccines without throwing any scientific or epidemiological jargon at you.
From what I have gathered from listening to both pro- and anti-vaxxers talk about vaccination, the major reason that people choose both to vaccinate, and not to vaccinate, their children is because they love their children immensely, and don't ever want them to come into harm's way. However, to put things into perspective, there is more research showing that salami is bad for humans than research showing that vaccines are harmful. I don't want to deny that there are indeed some very small risks to vaccination. Most of us have experienced some small side effects from some vaccines - like some pain at the site of injection, or feeling a bit feverish afterwards. Overall, though, vaccines are very safe because they are incredibly controlled. Scientists, who also sometimes have children and want to do everything they can to help them live healthy lives, work for decades to create the safest, most effective possible vaccines.
Before you ask, yes, I also won't deny that in very, very rare cases, people can have an allergic reaction to a vaccine. I invite you, though, to think of vaccination as going outside on a sunny summer day. It's not a pleasant thought, but every time any of us goes out, there is a very, very tiny risk that we could encounter something we are allergic to, or slip on ice, or have some other accident. However, we accept that tiny risk, because the benefits we get from going outside, running about, and having fun are so great compared to the risk that the choice seems easy. In the end, it's more risky to lock yourself up alone inside and avoid the risks of what you might encounter outside your house, than it is to venture out. The same is true of vaccines. By all published accounts based on real, reputable, trustworthy studies, the potential risks of not vaccinating are far, far greater than those of vaccinating.
Let's then get into the subject of what exactly is in vaccines. People often worry about the preservatives in vaccines, because they have scary sounding names. The one I've seen cited most is thiomersal, which contains mercury. Indeed - mercury is not good in large amounts. However, if you've ever eaten a can of tuna, you have probably eaten more mercury than there is in any vaccine. In fact, unless you were raised completely vegan, you have most likely already ingested more mercury than there is in all the vaccines you would get on any recommended vaccine schedule, since metals like mercury accumulate along the food chain. If you're worried about putting harmful compounds into your body, I would skip some meat and grow your own vegetables pesticide-free; this will more than make up for the tiny amounts scary-sounding compounds that you'll be exposed to with a vaccine.
The other thing in vaccines that scares people sometimes is that indeed, vaccines contain something related to the disease they protect against, which scientists call the "vaccine antigen". This antigen is usually a protein isolated from the bacteria or virus in question, or a dead or defective version of the microbe. The point of these antigens is to train your immune system to recognize the full-blown, actually harmful version of the microbe when you encounter it in the future. You can think of this like bringing your immune system to the kiddie pool, with arm-floaties on, before throwing it into the ocean. In today's highly globalised world, I can't stress how likely it is that your immune system will at some point end up in this "ocean" of bugs. Most people agree that it's a good idea to teach their child how to swim, if you have the means to do so, even though there are small risks that go along with that as well. Vaccination is the same: tiny risks, but big gains to starting out in the kiddie pool before diving fully in.
Finally, I want to quickly address the Wakefield study, the only study published that found that vaccines were associated with autism. This study was a bad study, and scientists as a community are terribly ashamed that this was ever published to mislead people. The original paper was found to be not only flawed, but outright fraud, and the doctor who led it was stripped of his license to practice medicine because of his carelessness. I would guess that the publishing of this study has harmed more kids than vaccines as a whole have, because of all the parents the study has misled.
To draw a comparison, the Wakefield study was kind of like the one that found that, on days when people bought more ice cream, more crimes were committed. "Oh no", the authors thought, "We should ban ice cream! Ice cream is a killer!"Luckily, somebody else looked at the study before publishing and found something else hidden. The temperature was the sneaky culprit! People commit more crimes when it's hot, and people buy more ice cream when it's hot. The temperature was the cause of the increased crime rates, not the ice cream. Similarly, the Wakefield study failed to identify the real culprit: age. Autism is often diagnosed around the same age that the MMR vaccine, the misidentified culprit, is given to children. The vaccine wasn't the cause at all (hundreds of studies have disproved the Wakefield study): age was the sneaky third factor. This problem of correlation versus causation is important in understanding how science works in general. Scientists are trained to remember that CORRELATION DOES NOT EQUAL CAUSATION. We must prove a direct the cause of ice cream for crime before we believe it is so.
I am sure that in this short post, I won't have addressed all of the questions, comments, and concerns that readers may have about vaccination. We all know that this is kind of a touchy subject. I invite you to send me any of those questions and concerns, nicely, and I'd be happy to write a follow-up post to this one!
For now - happy swimming!
~ Alex