Conspiracy - Vaccines Have Toxins in Them!

One of the most persistent claims made by anti-vaxxers is that vaccines have "toxins" in them and hence you should not get vaccinated. The two most common substances referenced by these fear-mongers are mercury and formaldehyde. 

The conspiracy has duped a lot of people as both mercury and formaldehyde are known by the public for their bad effects on health.  Once you do a little research you find that the claims related to these two substances can easily be refuted. 

So why is mercury in vaccines? Well this is a bit deceptive as mercury is not contained in vaccines on its own. It is instead part of a compound called thiomersal, which is perfectly harmless in the quantities found in vaccines. The problem is that most people don't understand that when you put an element into a compound, they have wildly different characteristics. You would be ill advised (to say the least) to consume pure chlorine, but when it's in the form of table salt I'd advise having some on your chips. As the fear of mercury in vaccines rose, the European Union and the United States removed thiomersal from routine childhood vaccines. As it was only used as a preservative this had little effect on the usefulness of the vaccines (thankfully). The fact that mercury is no longer in vaccines means that this can no longer be used as a reason not to vaccinate, even if thiomersal was a problem. 

Formaldehyde is the other frequently referenced "toxin" that vaccines contain. Formaldehyde is used on certain vaccines to inactivate the virus as a means to give people immunity. It is not in most vaccines, but those that it is contained in, have  just more than trace amounts of it. For example the polio vaccine contains 0.02mg/kg of formaldehyde. Obviously just giving you the concentration says nothing about whether or not it's dangerous in vaccines. However, the amount of formaldehyde is tiny compared to many common foodstuffs; for comparison (on average) bananas contain 16.3 mg/kg, potatoes contain 19.5 mg/kg and pears can have up to 60 mg/kg! The levels of formaldehyde in those foodstuffs are 815x, 975x and 3000x as high as in the polio vaccine, respectively. In light of this, not vaccinating because of formaldehyde seems pretty ridiculous.