We write a lot about vaccines here at Science-Based Medicine. Indeed, as I write this, I note that there are 155 posts under the Vaccines category, with this post to make it 156. This is third only to Science and Medicine (which is such a vague, generic category that I’ve been seriously tempted to get rid of it, anyway) and Science and the Media. There is no doubt that vaccines represent one of the most common topics that we cover here on SBM, and with good reason. That good reason is that, compared to virtually any other modality used in the world of SBM, vaccines are under the most persistent attack from a vocal group of people, who, either because they mistakenly believe that vaccines caused their children’s autism, because they don’t like being told what to do by The Man, because they think that “natural” is always better to the point of thinking that it’s better to get a vaccine-preventable disease in order to achieve immunity than to vaccinate against it, or because a combination of some or all of the above plus other reasons, are anti-vaccine.

“Anti-vaccine.” We regularly throw that word around here at SBM — and, most of the time, with good reason. Many skeptics and defenders of SBM also throw that word around, again with good reason most of the time. There really is a shocking amount of anti-vaccine sentiment out there. But what does “anti-vaccine” really mean? What is “anti-vaccine”? Who is “anti-vaccine”?

Given that this is my first post for SBM’s self-declared Vaccine Awareness Week, proposed to counter Barbara Loe Fisher’s National Vaccine Information Center’s and Joe Mercola’s proposal that November 1-6 be designated “Vaccine Awareness Week” for the purpose of posting all sorts of pseudoscience and misinformation about “vaccine injury” and how dangerous vaccines supposedly are, we decided to try to coopt the concept for the purpose of countering the pseudoscience promoted by the anti-vaccine movement. To kick things off, I thought it would be a good idea to pontificate a bit on the topic of how to identify an anti-vaxer. What makes an anti-vaxer different from people who are simply skeptical of vaccines or skeptical of specific vaccines (for instance, the HPV vaccine)? I don’t pretend to have the complete answer, which is why I hope we’ll have a vigorous discussion in the comments.

Believe it or not, I’m actually a relative newcomer to the task of taking on the anti-vaccine movement. Ten years ago, I was blissfully unaware that such a movement even existed; indeed, I doubt the concept would even have entered my brain that anyone would seriously question the safety and efficacy of vaccines, which are one of the safest and most efficacious preventative medical interventions humans have ever devised, arguably having saved more lives than any other medical intervention ever conceived. Even six years ago, although I had become aware of the existence of the anti-vaccine movement, I considered them a small bunch of cranks so far into the woo that they weren’t really worth bothering with. Yes, I was a shruggie.

All of that changed not long after I started my first blog in December 2004. Approximately six months later, to be precise. That was when someone as famous as Robert F. Kennedy, Jr. published an infamous screed simultaneously in Rolling Stone and Salon.com entitled Deadly Immunity that was so full of misinformation, pseudoscience, and conspiracy mongering that it altered the course of my blogging forever. Although I had already been becoming less and less of a “shruggie” about the anti-vaccine movement before RFK’s propaganda piece, “Deadly Immunity” resulted in a significant percentage of my blogging turning to discussions of the anti-vaccine movement and the scientifically-discredited myth that vaccines cause autism.

Anti-vaccine, not pro-safe vaccine

Before I try to define “anti-vaccine” in more detail, I should take a moment to point out that, if there’s one thing I’ve learned in nearly six years blogging about vaccines and the pseudoscience used to attack them, it’s that no one — well, almost no one — considers himself “anti-vaccine.” This is very easily verifiable in the outraged reaction elicited from people like J.B. Handley (who simultaneously gloats about the decline in confidence in vaccines among parents), Jenny McCarthy, and Dr. Jay Gordon when they are described as “anti-vaccine. Jenny McCarthy, for instance, will reliably retort, “I’m not ‘anti-vaccine.’ I’m pro-safe vaccine.” An alternative response is, “What I really am is ‘anti-toxins’ in the vaccines.” Meanwhile, Dr. Gordon will say the same thing while simultaneously saying that he doesn’t give a lot of vaccines and foolishly admitting in the comments of a blog post that some parents have actually had to persuade him to vaccinate “reluctantly.”

The rule that those holding anti-vaccine views will rarely admit that they are anti-vaccine is a good one, although there are exceptions. It is not uncommon to find in the comments of anti-vaccine propaganda blogs like Age of Autism and anti-vaccine mailing lists comments proclaiming explicit anti-vaccine views loud and proud, with declarations that “I am anti-vaccine.” This dichotomy has at times caused problems for the more P.R.-savvy members of the anti-vaccine movement, as demonstrated two years ago at Jenny McCarthy’s “Green Our Vaccines” rally, where images of vaccines as toxic waste and weapons of mass destruction were commonplace. Even so, the “Green Our Vaccines” slogan and coopting the “vaccine safety” mantle have been very effective for the anti-vaccine movement. In particular, Barbara Loe Fisher has successfully portrayed her National Vaccine Information Center (NVIC) as being a “vaccine safety watchdog” group looking out for parents’ rights, this despite hosting an online memorial for vaccine victims and a deceptive and disingenuous vaccine ingredient calculator.

“I know it when I see it”

In a concurring opinion in Jacobellis v. Ohio, regarding possible obscenity in a movie, Justice Potter Stewart once famously wrote:

I shall not today attempt further to define the kinds of material I understand to be embraced within that shorthand description [“hard-core pornography”]; and perhaps I could never succeed in intelligibly doing so. But I know it when I see it, and the motion picture involved in this case is not that.

From my perspective, defining what is “anti-vaccine” is a lot like defining obscenity: I know it when I see it. However, as in the case of pornography, even though it’s quite true that what is anti-vaccine is in general easily identifiable to those of us who pay attention to such matters, it’s much more difficult to define in a way that those who don’t pay attention to the issue can recognize. This difficulty is complicated by the fact that there are a number of different flavors of anti-vaccine views ranging from (I kid you not) the view that vaccines are a tool of Satan to depopulate the earth to much milder views. It’s also important to realize that most parents who buy into anti-vaccine views do so out of ignorance, because they have been misled, rather than due to stupidity. When I “go medieval” on anti-vaccine activists, my ire is almost always reserved for the leaders of the anti-vaccine movement, who spread misinformation.

When I’m actually in an exchange with someone whom I suspect of having anti-vaccine views, one rather reliable way of differentiating fear from real anti-vaccine views is to ask a simple question: Which vaccines do you think that, barring medical contraindications, children should receive? If the answer is “none,” then I’m pretty much done. I know I’m almost certainly dealing with an anti-vaccinationist. Be aware that this question may require some pushing to get an answer. Rarely am I able to get a definitive answer on the first try, because most anti-vaccine advocates are cleverer than that. They realize that I’m trying to get them to admit that they are anti-vaccine. Even so, if I ask something like, “If you had it to do all over again, would you vaccinate your child?” or “If you have another child, will you vaccinate that child?” I will usually get the candid response I’m looking for.

“Vaccines don’t work”? “Vaccines are dangerous”? They’re both!

If you look at the types of arguments used to oppose vaccination, they will almost always boil down to two different flavors, either that vaccines don’t work or that vaccines are somehow dangerous. Of course, we discuss the latter argument here all the time when we point out studies that refute the alleged link between vaccines and autism. Like the slogan “Tastes great, less filling,” both of these claims often co-exist to differing degrees, with some anti-vaccinationists arguing that both are true: Vaccines don’t work and they are dangerous.

This being the real world, one has to remember that vaccines are not perfect. They are not 100% effective, and there can be rare serious side effects. What differentiates anti-vaccine cranks from, for example, scientists who deal with issues of efficacy versus side effects and potential complications all the time, is exaggeration far beyond what the scientific data will support. For example, if the influenza vaccine is less efficacious than perhaps we would like (which is true), then it must be useless. This is, in essence, the Nirvana fallacy, wherein if something is not perfect it is claimed to be utterly worthless. Part and parcel of this approach involves the complement, namely vastly exaggerating the potential side effects and complications due to vaccines to paint them as being far more dangerous than the diseases they prevent. In addition, anti-vaccine activists frequently attribute harms to vaccines that the existing scientific data definitely don’t support as being reasonable or legitimate. The claim that vaccines cause autism is the most famous, but far from the only one of these sorts of claims. It’s not uncommon to hear fallacious claims that vaccines cause autoimmune diseases, asthma, and a general “weakening” of the immune system, among others.

One of the most famous examples of exaggerated harm or nonexistent risks is the infamous “toxin” gambit. This fallacious argument claims that there are all sorts of scary chemicals in vaccines. Of course, there are all sorts of chemicals with scary names in vaccines, just as there are all sorts of chemicals with scary names in almost everything, from food to clothing to household cleaners, among others. The dose makes the poison, and the amounts of these chemicals, such as formaldehyde, are tiny. As we’ve pointed out time and time again, for instance, the amount of formaldehyde in vaccines is so tiny that it’s overwhelmed by the amount of formaldehyde made as a byproduct of normal metabolism. Then, of course, there are the chemicals claimed to be in vaccines that are, in fact, not in vaccines. The most famous of these is undoubtedly the infamous “antifreeze in vaccines” gambit. Finally, there is the claim that there are “aborted fetal parts” in vaccines. This particular claim comes from the fact that, for some vaccines, the viruses used to make the vaccines are grown in a human cell line derived from an aborted fetus.

Overall, the “tastes great, less filling”-type anti-vaccine claims that vaccines are dangerous and don’t work, can be differentiated from scientifically valid concerns about the efficacy and safety of vaccines on the basis of how evidence is treated and the types of arguments that are used. Scientists, of course, tend to be a lot more measured and express the level of uncertainty in their claims; anti-vaccine activists are under no such constraints. When, for example, scientists debated how to respond to the H1N1 pandemic last year, there was considerable uncertainty about how to do it, when to do it, and how to formulate the vaccines. Which adjuvants? Should we use squalene in order to decrease the amount of antigen used? Contrast this to the anti-vaccine arguments, which tended to argue that H1N1 wasn’t harmful, that the vaccine was toxic and wouldn’t work, and even that it was a New World Order plot.

Approaching the evidence

If there’s one thing that distinguishes science from the way movements like the anti-vaccine movement approach evidence, it’s that the anti-vaccine movement values anecdotes over careful science. If you check out Generation Rescue’s website or any of a number of anti-vaccine websites, you will find numerous stories using the classic post hoc ergo propter hoc fallacy that in essence argues that, because one thing happened before another, that thing must have caused it. Because Generation Rescue preaches that its various forms of biomedical woo can “recover” autistic children, not surprisingly, there are a number of testimonials on its website touting stories of children who regressed after vaccination and then appeared to recover after whatever woo du jour was tried on them. On the surface, these testimonials seem convincing. However, given that millions of children who undergo vaccination each year, the number of vaccinations in the currently recommended schedule, and the fact that approximately 1% of children will eventually be diagnosed with an autistic spectrum disorder, it is not surprising, given the law of large numbers, that there will be a significant number of children who regress in fairly close temporal proximity to a vaccination by random chance alone. Even though such cases are random, though, to a single observer, they appear all the world as though the vaccine caused the regression. What’s difficult for non-scientists (and even many scientists) to accept is that it’s impossible to tell if vaccines are actually correlated with regression unless careful studies are done comparing large populations to determine whether children who are vaccinated really do have a higher chance of autism. Those studies have been done, and the answer is a resounding no. To the anti-vaccine movement, anecdotes trump evidence. Indeed, even physicians, like Jenny McCarthy’s son Evan’s pediatrician Dr. Jay Gordon, fall for touting their own anecdotal experience over careful epidemiology and science.

Perhaps one of the most characteristic aspects of the anti-vaccine movement is the same one that is shared by virtually every denialist movement, be it denying the science of climate change, evolution, or scientific medicine. That is the use of logical fallacies, cherry picking of the evidence, and distortion of the science. Perhaps the best example of cherry picking and distortion of evidence engaged in by anti-vaccine activists is a set of graphs I discovered earlier this year by a man named Raymond Obomsawin, in which he tried to represent as “proof vaccines didn’t save us.” As I pointed out in my response, this was intellectual dishonesty at its most naked. Basically, Obomsawin deceptively conflated mortality and incidence. Worse, he also chose his graphs in a way that parts of the data were left out. Indeed, less than a month ago, the Australian anti-vaccine activist Meryl Dorey approvingly cited Obomsawin’s graphs. When it was pointed out how Obomsawin had cherry picked his graphs to deceptive purpose, his response was beyond pathetic:

The software that I was using to create the graph did not allow for the creation of either a blank space or a dotted line between 1959 and 1968. There was no intent to be dishonest about this, and thanks to your blog, I will make it a point to specifically note on the graph that there is an absence of incidence data in this period.

I note that, not only have the graphs not been changed as far as I can tell, but Dr. Obomsawin is going to be giving a webinar tomorrow in which he is apparently going to argue the same nonsense. I’m half tempted to sign up and see what he says. It’d make for more blogging material, and an update to the Obomsawin Technique of vaccine denialism (yes, I named it after him) is probably overdue anyway. After all, I never took on several other of the graphs he included in his collection. My guess is that Obomsawin won’t change his graph. Obomsawin’s disingenuous approach to the evidence is mirrored by naturopath David Mihalovic, who wrote the infamous 9 Questions That Stump Every Pro-Vaccine Advocate and Their Claims. Dr. Crislip answered each and ever one of these “nine questions” without difficulty. The result was that Medical Voices (which published Mihalovic’s post) challenged us to a “public debate.” We said we’d be happy to debate them in blog posts but that a “public debate” would be counterproductive and allow them to engage in the Gish Gallup. The result? Like Brave Sir Robin, Medical Voices bravely turned its tail and fled. “9 Questions” remains on the impressively named International Medical Council on Vaccination’s website, formerly known as Medical Voices.

Another example of how anti-vaccine activists approach the evidence landed with a huge thud in the blogosphere last year when the Jenny McCarthy-fronted anti-vaccine group Generation Rescue decided to try to discredit the studies that show no link between vaccines and autism. As Steve Novella, Mark Crislip, and I all showed, Generation Rescue’s arguments were fallacious at best and deceptive at worst. The result was that J.B. Handley launched a broadside at Steve Novella.

Which brings us to another characteristic of the anti-vaccine movement.

Conspiracy mongering and reaction to criticism

Science is, if you’ll forgive the term, a highly Darwinian process. To be a scientist, you have to have a thick skin, because you’ll need it. Reviewers, mentors, other scientists, and virtually anyone to whom you present your results will be picking away at them, looking for flaws, looking for reasons to invalidate your conclusions. There’s nothing personal in it (usually); it’s how the process of science works. Similarly, those who have an appreciation for science understand that it’s a rough-and-tumble world where scientists have to be able to defend their work. Yes, it’s messy as hell, but it works. It may take a lot longer than we’d like and be a lot more confusing than the public likes, but over time hypotheses that don’t hold up are weeded out, to be replaced by those that do. Scientists understand this, and most know not to become too distressed by criticism. True, scientists are human too and can’t always separate themselves from their science; sometimes they lash out at criticism. However, for the most part, they don’t react the same way as denialists do when criticized. More importantly, contrary to scientists, it’s very rare indeed for an anti-vaccinationist to change his mind due to the evidence.

The anti-vaccine movement shares another characteristic with denialists of all stripes, and that’s an intolerance to criticism. Instead of answering it with science (which they can’t do), they tend to answer criticism with vitriol and conspiracy mongering. After all, when it’s all a conspiracy between the government and big pharma to “suppress” the data that allegedly show that vaccines cause autism, then anyone who speaks out for that viewpoint must be a pharma shill. If that critic is a woman, then she must have been the victim of a date-rape drug. Or he must be hopelessly compromised by relationships between big pharma and his university, even if such relationships need to be made up or extrapolated beyond all relationship to reality.

Perhaps the best way of describing how anti-vaccine groups react to criticism is to point out that their first response tends to be to try to suppress criticism rather than to answer it. Usually, this is accomplished through ad hominem attacks and poisoning of Google reputations. One particularly egregious example occurred when Age of Autism Photoshopped the faces of Steve Novella, Trine Tsouderos, Alison Singer, Paul Offit, Amy Wallace, and Tom Insel into a photo of people sitting down to a Thanksgiving feast of dead baby. Yes, likening enemies to cannibals wasn’t going too far. Sometimes attacks on critics can escalate to legal thuggery, which happened when the British Chiropractic Association sued Simon Singh and Barbara Loe Fisher sued Paul Offit. That such lawsuits nearly always fail, at least in the U.S., where the libel laws aren’t as draconian as in the U.K., doesn’t matter. The goal is not to recover damages; it’s to intimidate critics into silence. Unfortunately, even I’m not immune to being at the receiving end of this tactic.


Distinguishing true anti-vaccine rhetoric from cluelessness is not always easy. To help, I’ll recap the eight characteristics I’ve just discussed:

  1. Claiming to be “pro-safe vaccine” while being unrelentingly critical about vaccines
  2. The “vaccines don’t work” gambit
  3. The “vaccines are dangerous” gambit
  4. Preferring anecdotes over science and epidemiology
  5. Cherry picking and misrepresenting the evidence
  6. The copious use of logical fallacies in arguing
  7. Conspiracy mongering
  8. Trying to silence criticism, rather than responding to it

Someone who is anti-vaccine will almost certainly use at least three or four of these techniques. The cranks at Age of Autism use all eight and then some. Indeed, when these eight techniques fail to suffice, they make up more.

One other thing that’s important to mention, particularly since I’ve been guilty of this sin on occasion, is that we have to be careful about leaping to the conclusion that someone is anti-vaccine. That’s where the “I know it when I see it” test can backfire. For example, I was quite distressed at some of the statements coming from Dr. Marya Zilberberg on vaccines, in particular her referring to defenders of the current vaccine schedule as “rabid” and arguments that are reminiscent of the same sorts of arguments that the anti-vaccine movement uses for the HPV vaccine and the chickenpox vaccine, mixed with a question about combinations of vaccines being of concern that sounded uncomfortably like the “Too Many Too Soon” slogan beloved of Generation Rescue. Although I did not explicitly call her “anti-vaccine” in another forum and even went out of my way (as did Steve) to point out that I don’t think she’s anti-vaccine, I did try to point out to Dr. Zilberberg that, if you’re skeptical of some aspect of our current vaccination schedule, it’s important to be aware of how anti-vaccine cranks argue, so that you don’t inadvertently sound like one.

In the end, the anti-vaccine movement is another denialist movement, very similar to denialists of global climate change, science-based medicine, and evolution. As such, it uses many of the same fallacious strategies and distortions of science to promote its agenda and reacts the same way to criticism. Similarly, in the end, the anti-vaccine movement is also far more about ideology rather than science, which is why it remains so stubbornly resistant to reason and science. Finding an effective means to counter its message will likely require developing effective general strategies to counter science denialist movements of all types.

Let the discussion begin! What are the characteristics of anti-vaccine arguments and organizations that allow us to identify and characterize them as “anti-vaccine”?

Posted by David Gorski

Dr. Gorski's full information can be found here, along with information for patients. David H. Gorski, MD, PhD, FACS is a surgical oncologist at the Barbara Ann Karmanos Cancer Institute specializing in breast cancer surgery, where he also serves as the American College of Surgeons Committee on Cancer Liaison Physician as well as an Associate Professor of Surgery and member of the faculty of the Graduate Program in Cancer Biology at Wayne State University. If you are a potential patient and found this page through a Google search, please check out Dr. Gorski's biographical information, disclaimers regarding his writings, and notice to patients here.