Vaccinate Your Spawn

The anti vaccine movement has gained a fair amount of attention early this year. The World Health Organization (WHO) has labeled vaccine hesitancy one of it's top ten threats to global health. Measles is making a comeback in the United States. Particularly near Portland, OR where a large outbreak has risen to 50 cases as of 4 Feb. The anti-vaccine movement is nothing new; there have been anti-vaxxers probably as long as there have been vaccines. There's even a popular depression era cartoon making fun of them:

The specific claims about vaccines have been debunked time and time again. As such I will not present here an exhaustive list of them, as this topic will no doubt come up again, but instead discuss the ones that come up most when I talk to other parents.

Before I get into the weeds here, I'd like to say that it is 100% okay to be concerned about what is going on with your child's medical care. Illness is frightening for us parents and painful for children. It makes perfect sense to want to avoid anything that might hurt your child. So when anti-vaxxers elect not to vaccinate it is important to be compassionate, knowing their heart is in the right place, and to be humble, knowing that we too are susceptible to the cognitive errors that lead people to this unfortunate decision.

When it come to vaccines the most common thing I hear from concerned parents is that they are concerned about the ingredients in the vaccines. The most common of ingredient feared that I've come across is thiomersal. Thiomersal is a mercury containing compound used as a preservative in vaccines. Hearing that there is mercury in this compound often scares people. Mercury is, after all, a very dangerous compound. But two things need to be understood when you hear about "scary chemicals" like this. One, the dose makes the poison; there is an amount of anything that your body will become overwhelmed by. Two, the properties of an atom change when they are bound in a molecule. The most common example of this is sodium chloride: table salt. Sodium explodes on contact with water and chlorine is a toxic gas. When they bond they go great on fries. The amount of thiomersal in vaccines is minuscule, containing around 8 to 50 µg per dose. Based on toxicity data this means that a 25 kg child would need to take at least 37,500 vaccines to be harmed by them; which is a pretty crazy number.

The next most common ingredient causing fear is fetal tissue. There is one major flaw with this thinking: fetal tissue, or DNA (a common, related claim), is not an ingredient in vaccines. Some vaccines do use cell lines derived from fetal tissue from the 1960's but it is in no way in the final product.

Another common source of concern among parents is that vaccines list a host of "adverse reactions" found in the package insert. To be fair, there is a list of adverse reactions that can be found in the package insert but, as with everything, it is more complicated than what it seems. There is a good overview of how to interpret the sections in an insert over at Skeptical Raptor. The big thing you should take away from that is this:

[the adverse reaction] sections lists all side effects observed in all studies of the drug (including post-marketing studies), whether or not it has been scientifically established there is a causative link between the drug and the side effect. Almost all of these side effects are coincidental observations and are rarely of much concern. ... These are simply observations.

That is to say, the adverse reactions are anything that happens to you even if it had nothing to do with you getting a vaccine. Say you get bloody noses regularly. If you went on a vaccine trial and some time after administration of a vaccine you get one again they have to list it in the insert, even though the cause is known. So take all those scary conditions listed with a grain of salt.

The last thing I'd like to address is the fear of your child getting some mental condition (most commonly autism). Thanks to Andrew Wakefield there is the irreparable belief that vaccines cause autism. This, however, is not the case. Study after study, after study, after study has found no connection between autism an vaccines. Of all the things to worry about, getting autism from vaccines shouldn't even be on your radar.

My kid are, and will continue to be, up to date on their vaccines. Thanks to science, there is no doubt in my mind that vaccines are the most important medical tool we have at our disposal. I question myself about a lot of things I choose to do concerning my kids. Vaccines are not one of those things.