The following is a guest post from Brendan Curran-Johnson, who was one of our presenters at last year’s SkeptiCamp. Here, Brendan responds to a few of the claims made in an image that’s currently circulating on Facebook, which originates from the hilarious den of conspiracy nuttery that is Truther.org.

While I certainly support people learning more about vaccines (because science and learning are awesome), avoiding vaccines has very real health consequences that affect more than just the people not taking the vaccines. In the past few years there has been a resurgance of a number of diseases that we had under control (pertussis, mumps, measles, etc.).

Most people cite the MMR/Autism connection when talking about the harms of vaccines, but the truth is that the study that is based on (the Wakefield study originally published by the Lancet) is not a valid study. The Lancet retracted it, and Wakefield was actually accused of deliberate fraud.

There certainly have been cases of drugs turning out to be harmful (thalidomide being the most obvious example), the process which the FDA and Health Canada use to screen drugs is very rigorous. The process is not perfect (no system could be 100% effective), but it is the most reliable system that anyone has come up with.

This is in stark opposition to homeopathy, which this photo advocates (kind of—marijuana and refusing prescription drugs have nothing to do with homeopathy). Alternative medicine (which is what they really are trying to advocate) suffers the problem that it has either not proven to be effective, or has been proven to not be affective (alternative medicine that has been proven to work is called medicine).

Homeopathy in specific is one of the silliest ‘medicines’ that exists. The two basic precepts of homeopathy are that like cures like (e.g., if someone is having trouble breathing, the proper medicine would be something that also restricts breathing), and that the more you dilute something, the stronger it gets. The typical dilution of homeopathic medicine is 30C. The system works as follows: take 99 parts water and 1 part ‘medicine’. That would be 1C. To make 2C, take 99 parts water and 1 part 1C ‘medicine’. The amount of dilution is 1 part per 1,000,000,000,000,000,000,000,000,000,000,000,000,000,000,000,000,000,000,000,000. If you were to make a sphere of water that stretched from the earth to the sun, you would add just one molocule of ‘medicine’ (that statistic is taken from Dr. Ben Goldacre’s Bad Science).

The advice being given here isn’t just wrong, its actively dangerous (also counter to point 8: avoid fear, propoganda, disinformation). Medicine is far too important a subject to allow misinformation to be spread unchallenged.

Thanks, Brendan!