When someone pro or against vaccines gives you a piece of scientific literature to assess, how do you know if it is good? How do you know if it is excellent work or just an opinion wrapped in some tables? A warning:
Just because it is published in what appears to be a credible journal does not mean it is good work!
Literally, there are dozens of crap journals in alternative and complementary medicine, new earth creation and other bogus disciplines. In the days of the internet a journal is easy to produce, so you need to know what is real and what is junk.
Start with where it is published. Let's start with two examples given to me this week by an anti-vax friend. These are three articles that she claims support the position that vaccinations are dangerous. Are these valid peer-reviewed, top-tier research papers? Let's see!
The two papers are
1. Adams et al., 2009 The Severity of Autism Is Associated With Toxic Metal Body Burden and Red Blood Cell Glutathione Levels. Journal of Toxicology 2009
2. Geier et al., 2009 Mitochondrial dysfunction, impaired oxidative-reduction activity, degeneration, and death in human neuronal and fetal cells induced by low-level exposure to thimerosal and other metal compounds. Toxicological and Environmental Chemistry
First, let's check impact factor. Impact factor is a term used to rate how often other scientists refer to your work in their publications. Some of my papers have been cited over 100 times and these are in journals with impact factors of 6-10.
For a real journal you'll get a number and the higher the number the better. Nature and New England Journal of Medicine are around 29. This means that 29 other papers cite the average article in the following year. It means that the science is good and grows.
How do you find Impact Factor? Look online. Go to Journal Citation Reports and type in the journal name. Go ahead. See what you get. If you can't get JCR, just Google "Journal of Toxicology Impact Factor". Check the other one.
How about J of Toxicology? Well it's a little journal from a publisher in India. It doesn't get an impact factor. Why? Usually it means that papers are not peer-reviewed (authors can either pay to publish, publish without review, or have the work "communicated" by someone that agrees with it). It also may mean that the journal does not have an Editorial Board with substantial recognition. Basically, it is a low venue to show your best work.
I checked with the editor of Toxicological and Environmental Chemistry and he says that papers just have to be gone over by two colleagues of the authors. So, if you have a junk science study that you want published you can have two buddies that share your ideological blinders look at it and approve it. That's absolutely horrible.
By the way, good journals still have impacts of 3.o and some with minor impact are in the 1's but still have good data. To no get on the list, or even considered, shows how bad these anti-vax studies are.
So let's end there. The two best, most recent pieces of scientific evidence that anti-vax interests believe show conclusively that vaccines are dangerous are published in obscure journals. These are places where only anti-vaxers read and no scientist ever cites going forward (except for those that hold it up at crap science- that still raises impact factor!).
Do you want to base your sound medical decisions on these papers, or stuff in the New England J. Medicine or Cell? You decide. Your doctor wants you to go with NEJM and Cell, the anti-vaxers want you to go with the results (that we haven't yet destroyed, but we'll get to that) in the obscure, no-impact journals. That is their best science.
What do you want as the scientific foundation for your medical decisions?
(In the next two days I'll rip these two scientifically bankrupt studies apart with scholarly rigor)