This is the first of a series of posts adapting a presentation made at The Ontario Public Health Convention in April, 2011. The presentation, “Fighting in the Trenches: Countering Anti-Vaccine Sentiment with Social Media” was a panel discussion from Scott Gavura and Kimberly Hébert:
One of the best parts of the infectious disease outbreak movie Contagion was the decision to include an antivaccinationist, conspiracy-minded, alternative health advocate, played by Jude Law. Law gave a character-perfect performance of someone intent on deliberately and selfishly thwarting public health advice, putting lives at risk as a consequence. Sadly, the writers didn’t have to look far for real world examples: It’s hard to forget “Health Ranger” Mike Adams’s paranoid music video produced in 2009, at the height of H1N1, when he decided to put every antivaccine argument into one performance.
But the Health Ranger is just the current manifestation of antivaccine sentiment which has been around since vaccines were invented:
When a theory has been confirmed so completely by facts as has the proposition that vaccination effectually performed will prevent an individual from contracting small-pox, or at least so fundamentally modify the disease that it is no longer a serious malady, there is in many minds a natural distaste to fight the battle again or to be constantly defending the position against the attacks of ill-informed or prejudiced persons.
- British Medical Journal, July 24, 1897
But this battle is still being fought, after over 100 years of immunization, and over two dozen diseases becoming vaccine-preventable. The anti-vaccine movement is a real movement, and it’s doing what it can to create fear, uncertainty and doubt regarding public health messaging. There is evidence that antivaccinationists can influence vaccination decisions. The arrival of social media over the past decade means there’s the need for public health advocates to adapt their messaging to this new medium. What seems clear is that “traditional” public health tactics, with warnings and arguments from authority, are dwindling in their effectiveness. All aspects of medicine are moving towards models of shared decision-making. This is an overdue change, and it’s been facilitated by the widespread availability of health information. Information is no longer hidden from public access. Want the approved product monograph for a vaccine? It’s available online. Even the primary literature is becoming more freely accessible.
Unfortunately, the power of the Web 2.0 and social media has made it easier for antivaccinationists to foster antivaccine fears and sentiment. In order to combat this misinformation, the movement’s tactics and tropes must be understood, so they can be called out.
There are several excellent websites, including Respectful Insolence and Science-Based Medicine, that have dozens if not hundreds of posts on the tactics antivaccine movement. And Skeptic North has more than just about any other Canadian source. Anna Kata in the Department of Anthropology at McMaster University in Hamilton has summarized the antivaccine movement’s actions in the paper, Anti-vaccine activists, Web 2.0, and the postmodern paradigm – An overview of tactics and tropes used online by the anti-vaccination movement. She neatly categorizes the disingenuous tactics and messaging used by the antivaccine movement. Tactics include:
- Skewering the science of vaccine safety and efficacy, while trying to create legitimacy for unfounded or discredited theories of harm. Antivaccine advocates denigrate legitimate scientific studies, and the scientific process in general, why also trying to bolster scientific credibility for their own theories. Pseudoscientific conferences, like those offered by AutismOne, give the veneer of legitimacy to disproven beliefs.
- Shifting the hypotheses and the villain, from MMR, to thimerosal, to other “toxins”, and more recently, “too many, too soon”.
- Censoring criticism, whether it’s at Age of Autism, Mothering.com, or other antivaccine sites that delete comments or restrict access to their events, creating virtual or real echo chambers.
- Attacking the opposition, whether it’s David Gorski at Science-Based Medicine or lawsuits against physician Paul Offit or journalist Amy Wallace.
Tropes are language or literary devices that are intended to achieve a specific effect. Not quite a a cliché, they’re recurring themes that, in the context of the anti-vaccination movement, are used to create fear, uncertainty and doubt about vaccines. Kata’s paper included 14 tropes – I estimate there are at least 30, if not more. Recognizing antivaccine tropes is a key skill in countering antivaccine propaganda.
1. “I’m not anti-vaccine, I’m pro-safe vaccine”
Antivaccine advocates are reluctant to admit that they fundamentally oppose vaccination. So a common tactic is denying the opposition of vaccines, but instead arguing that one is in favour of safer vaccines. This trope, when taken literally, is hard to argue with – who could be against products that are safer? This is a straw man argument. No public health advocate argues against safe vaccines. Yet 100% safety in anything is impossible to guarantee. Vaccines have risks and benefits, with the benefits dramatically outweighing the risks. But to antivaccinationists, “evidence” is listed to imply that vaccines could be easily made safer – if only manufacturers would listen! But looking more closely at the arguments reveals misleading information and distorted representations of scientific information.
Further Reading: Jenny McCarthy, Jim Carrey, and “Green Our Vaccines”: Anti-vaccine, not “pro-safe vaccine” (Science-Based Medicine), The annals of “I’m not anti-vaccine,” part 9 (Respectful Insolence), Once again: Antivaccine, not pro-safe vaccine (Respectful Insolence), “Green Our Vaccines”: “Pro-safe vaccine” or anti-vaccine? You be the judge! (Respectful Insolence)
2. “Vaccines are Toxic!” aka The Toxin Gambit
This is an argument with a false composition:
- “x” is toxic
- vaccines contain “x”
- Therefore, vaccines are toxic
Antivaccinationists cannot or will not understand that “the dose makes the poison”. Instead they link the consequences of exposure to vaccine ingredients at other settings and doses, declaring vaccines to be unsafe in he process. The goalposts keep moving with this trope: The toxin used to be thimerosal. Now that thimerosal has been removed from almost all vaccines, and the incidence of autism hasn’t changed, other ingredients are blamed. Whether it’s formaldehyde, squalene, aluminum, or some other component, the scientific evidence doesn’t stop claims like, “FDA Approved H1N1 Vaccines Contain Ingredients Known to Cause Cancer and Death!” This argument is just a distraction from the main issue of the antivaccinationist: The vaccine itself. It’s always the vaccine.
One particularly misleading tactic used by antivaccinationists to emphasize vaccine toxicity are “vaccine calculators” that are crafted to frighten you into avoiding vaccinations.
Further Reading: Toxic myths about vaccines (Science-Based Medicine), The “toxin gambit” on steroids (Respectful Insolence), A Defense of Childhood Influenza Vaccination and Squalene-Containing Adjuvants; Joseph Mercola’s “Dirty Little Secret” (Science-Based Medicine), Cries the antivaccinationist: Why are we injecting TOXINS into our babies? (revisited) (Respectful Insolence)
3. “Vaccines should be 100% safe”
If a vaccine cannot be shown to be 100% safe, it is suspect, according to this trope. Another straw man argument, it ignores any meaningful evaluation of risk and benefit. It further ignores the fact that no health care professional denies that vaccines are not risk free. However, they are much safer than the diseases from which they are designed to protect. While few doubt the benefit that seatbelts offer, the fact that they do not prevent deaths under all circumstances is usually not cited as reason to avoid using them. In fact, it’s because of the actual evaluation of risk and benefit that some vaccines are not appropriate for some individuals under some circumstances. Rather than use science-based information, NVIC’s Physician’s Warranty of Vaccine Safety is a tool created by antivaccinationists for parents to give to their physician. With a combination of misleading and demonstrably incorrect statements, no physician is likely to sign the document, providing the impression that vaccines are unsafe. Antivaccinationists will also point to adverse event surveillance systems and the Vaccine Injury Compensation Program as evidence of the harms of vaccines, again ignoring any serious evaluation of benefit and risk.
Further reading: Institute for Vaccine Safety, Vaccine Safety (Every Child by Two), Adverse Effects of Vaccines: Evidence and Causality (Institute of Medicine), Yet another bad day for the anti-vaccine movement 2011 (Respectful Insolence)
4. “You can’t prove vaccines are safe”
This argument flips the onus onto vaccine advocates, implying that because there is no clear cause of certain conditions or events, then vaccines are suspect. It’s another faulty argument:
- There is no conclusive cause of autism
- Children receive vaccines
- Therefore, vaccines are a potential cause of autism
There is truth to the statement that it is impossible to completely prove a negative hypothesis. However, when huge epidemiological studies fail to detect any causal relationship, it’s reasonable, based on the evidence, to conclude that no relationship exists. Multiple lines of evidence support this conclusion. The burden of proof is now on the group making the association – and no credible scientific evidence exists to support that hypothesis. In fact, epidemiological evidence suggests that vaccination is very safe – one of the safest health interventions we make.
Further reading: Vaccine safety information and resources (CCIAP), The incredible shrinking vaccine-autism hypothesis shrinks some more (Science-Based Medicine), The HPV Vaccine (Gardasil) Safety Revisited (Science-Based Medicine)
5. “Vaccines didn’t save us” aka “Vaccines don’t work”
This is a frequent and deceptive tactic, suggesting that sanitation and other public health measures can protect against disease adequately, and therefore the vaccine isn’t responsible for the decrease in the incidence of a disease. While it’s true that sanitary measures are essential components to preventing the spread of some diseases (e.g., influenza), it glosses over the scientific evidence demonstrating that most spread regardless of hygiene. Varicella would continue to infect up to 90% of the population by age 12 if it were not for vaccines. Graphs which are purported to demonstrate a lack of vaccine efficacy are drawn to be deliberately misleading.
Further reading: “Vaccines didn’t save us” (a.k.a. “vaccines don’t work”): Intellectual dishonesty at its most naked (Science-Based Medicine), Historical Comparisons of Morbidity and Mortality for Vaccine-Preventable Diseases in the United States (JAMA), Are vaccines effective? (Skeptic’s dictionary), Outbreaks (Science-Based Medicine), Analysis of Anti-Vax Graphs (Vic Skeptics), Measles Elimination in Canada (J Inf Disease), Measles Elimination in the United States (J Inf Disease), Measles deaths, pre-vaccine (Mystery Rays from Outer Space)
6. “Vaccines are unnatural”
A popular argument from alternative practitioners like homeopaths, chiropractors, and naturopaths, this trope is the naturalistic fallacy: Natural is good. Vaccines are unnatural, and therefore bad. Immunity conferred by (surviving a) disease is perceived to be superior and desirable to vaccination. This has led, unbelievably, to events like pox parties where infectious material is shared.The argument is an odd one in that vaccines induce an immune response, so that it’s the body’s own “natural” immunity which is then primed to identify and fight any future pathogen exposure. The naturalistic argument is among the weakest arguments: Deadly nightshade, botulism, and smallpox are all natural. But most people, if given the choice, would prefer to avoid them.
Further reading: Appeal to Nature (Fallacy Files), Moral Non-Naturalism (Stanford), “Pox packages,” child abuse, and the violation of federal law (Respectful Insolence), Vaccines are “transhumanism” that subverts evolution? (Respectful Insolence)
7. “You’re choosing between diseases and vaccine injuries”
This trope frames the discussion in a misleading way, excluding other possibilities, and creating a false dichotomy:
“I do believe sadly it’s going to take some diseases coming back to realize that we need to change and develop vaccines that are safe. If the vaccine companies are not listening to us, it’s their f___ing fault that the diseases are coming back. They’re making a product that’s s___. If you give us a safe vaccine, we’ll use it. It shouldn’t be polio versus autism.” – Jenny McCarthy, Time Magazine, 2009
Jenny McCarthy sees the resurgence of communicable disease as an acceptable consequence of her anti-vaccination drive. She rejects any responsibility from stoking anti-vaccine fears, when it’s clear that to McCarthy and other anti-vaccine advocates, no vaccine is safe enough to administer. Yet if there is no credible evidence linking vaccines to autism (as is the case) then there is no “choice” that needs to be made between the DPT vaccine and autism. Rather, the decision to take the vaccine should be based on an evaluation of the benefits and known risks – which is overwhelmingly positive for vaccines.
8. “Galileo was persecuted too!”
“To our community, Andrew Wakefield is Nelson Mandela and Jesus Christ rolled up into one” – J. B. Handley, co-founder of Generation Rescue
Also known as the Semmelweiss gambit or the Copernicus gambit, this is yet another logical fallacy: If your idea is criticized and ridiculed, it must be correct, even if (or perhaps especially when) all the scientific evidence points to the contrary. There are a number of ways this analogy is incorrect:
- Galileo Galilei was persecuted by the church, for ideas which contradicted church dogma – not scientific evidence.
- Galileo was an educated scientist and astronomer, not a critic armed with the 16th century equivalent of degree from Google U.
- There is no necessary link between being perceived as wrong, and actually being correct.
- Given the infinite number of incorrect statements for every established fact, the idea that an idea is being criticized for not being correct means it is more likely that idea is incorrect, rather than correct.
More current examples of the Galileo gambit cited by anti-vaccinationists include the discovery by Warren and Marshall that the main contributor to stomach and duodenal ulcers is the bacterium Helicobacter pylori. While there was initial skepticism of the idea, data emerged to change the scientific consensus, and in less that a decade, H. pylori was established and accepted as a cause of ulcers. Importantly, this change occurred because scientific evidence established it to be real. In contrast, antivaccinationism arguments are fundamentally hand-waving excuses to distract from the fact that the demonstrated benefits of vaccination greatly outweigh the risks of use. A more appropriate quote on Galileo is:
“Alas, to wear the mantle of Galileo it is not enough that you be persecuted by an unkind establishment, you must also be right.” — Robert L. Park
Perhaps not surprisingly, the stridently antivaccine organization Age of Autism has a Galileo Award. Its 2008 winner? Andrew Wakefield.
9. “Science was wrong before!”
“Falsus in uno, falsus in omnibus” – “False in one thing, false in all”. This argument is referred to as the thalidomide gambit (aka Gavura’s law), or the Vioxx gambit.
“Established science” refers the accumulated knowledge, that is supported by objective evidence, and is amended or updated when new evidence emerges. When scientific knowledge changes, it’s because newer theories provide a better explanation for observed effects than prior models (see the Galileo gambit, above). The argument that “science was wrong before” is usually used to defend statements which have usually been disproven. It confuses “science doesn’t know everything” with “science doesn’t know anything”, which reminds me of a classic Dara O’Briain clip. Any reference to “science was wrong before”, thalidomide, or Vioxx when it comes to antivaccination is a sign that the statement being made has no scientific evidence to support it. Science has been wrong before, but the scientific process isn’t wrong. If new evidence emerges to change the scientific consensus, it’s because of that process – not from ignoring it. Rational Wiki explains it as follows:
The fact that science can be “wrong” in this way is a feature, not a bug, as one of the differences between science and pseudoscience is that science is self-correcting whereas pseudoscience continues to put forth the same debunked points over and over again. These pseudoscientists present “science” as a monolithic entity with no difference between different types of science and the uncertainties associated with each field.
Further reading: Oh yeah? Thalidomide! Where’s your science now? (Science-Based Medicine), The appeal to “science was wrong before” (Skeptico), Science was wrong before (Rational Wiki), A crank’s favorite gambit: Falsus in uno, falsus in omnibus (Respectful Insolence)
10. “So many people can’t all be wrong” aka “argumentum ad populum”
This is a simple argument from popularity, sometimes called an appeal to a widespread belief or an appeal to common practice. When a statement is prefaced with “Everybody knows,” you’re looking at an argument from popularity. Science is not a popularity contest, and popularity does not indicate the validity of an idea. Rather, ideas must be evaluated based on their own merits, and the scientific evidence that support them. This argument is regularly used to defend practices which are popular but not supported by any scientific evidence, like homeopathy, integrative medicine, and also antivaccinationism. The argument from popularity is also the basis for different antivaccine petitions. Unfortunately for the antivaccine movement,, what is accepted science is not determined by vote.
11. “Skeptics believe…”
This phrase sets up a straw man argument which misrepresent pro-vaccine arguments and create easier targets to attack:
- “You believe all vaccines are safe and effective”
- “You believe we should just accept what our government tells us”
- “You don’t think autism is a real issue”
- “You believe in mandatory vaccination”
- “You believe it’s fine to inject a neurotoxin into an infant”
Illustrated nicely by Mike Adams the “Health Ranger”, and neatly rebutted by Steven Novella, these are arguments of the antivaccinationists’ own creation which appear everywhere on antivaccination websites. By creating false arguments, antivaccinationists use this tactic to avoid providing credible scientific arguments to support their own positions.
Further reading: Straw Man Fallacy (Skeptic’s Dictionary), Straw Man (Fallacy Files), A pyromaniac in a field of straw man or a black hole of burning stupid incinerating every straw man in the universe? Mike Adams attacks skepticism (Respectful Insolence)
12. “You’re in the Pocket of Big Pharma”
Any critic of the anti-vaccine movement will inevitably be called a shill for Big Pharma. It’s probably the most common ad hominem attack use by antivaccinationists, accusing public health supporters of being supported (financially or otherwise) by pharmaceutical companies. This accusation shifts the discussion to one where the public health advocate must act defensively regarding their motives, freeing the antivaccinationist from actually responding to the scientific evidence. It’s been used to attempt to deliberately poison the reputations of public health advocates such as David Gorski, Paul Offit, and others. But whether or not someone actually is being supported by a pharmaceutical company has no relationship to the scientific evidence. Antivaccinationists, lacking credible evidence to support their position, use ad hominems like the pharma shill gambit to avoid responding meaningfully to the scientific evidence.
13. “I don’t believe in coincidences”
This argument posits that correlation equals causation, another logical fallacy. With anti-vaccine arguments, this involves anecdotes about negative events which have occurred following vaccination, and the vaccine was blamed as a consequence. The anti-vaccine movie The Greater Good is essentially written around this premise. Recall during 2009 that the H1N1 vaccine was linked by antivaccinationists to numerous harms, including miscarriage. However, given the incidence of miscarriage (or heart attack, or stroke, or indigestion, or any other event) in the population, we can expect a huge number of medical events to occur following the administration of any vaccine, simply by chance alone. So the only way to determine if something is causal is to study it. Bradford Hill established nine criteria for evaluating causality, which serve as a useful template to evaluate harms attributed to vaccines:
- Strength of the association: How strong is the association between cause and effect?
- Consistency of the association: Do other studies support the same association? What about a control group?
- Specificity: Does altering only the cause alter the effect?
- Temporal relationship: Does the cause precede the effect?
- Biological gradient: Is there a dose-response relationship?
- Biological plausibility: Does it make sense? Does it violate well established scientific evidence?
- Coherence: Does the evidence fit with what is known of the natural history of the disease?
- Experimental evidence: Are there any clinical studies supporting the association?
- Reasoning by analogy: Is the observed association supported by similar associations?
In the case of vaccine-related harms like vaccines and autism, no causal relationship exists.
Further reading: Statistics for Skeptics Part 2 – Correlation vs. Causation (Skeptic North), Evidence in Medicine: Correlation and Causation (Science-Based Medicine), Causation and Hill’s Criteria (Science-Based Medicine)
14. “I’m an expert on my own child”
This argument is used to denigrate scientific evidence and genuine knowledge about vaccine safety, arguing that relevant expertise is inappropriate or unnecessary. A postmodern argument, it redefines expertise in ways that may be empowering, or at least offer more flexibility to the anti-vaccine argument. In some ways this argument can also illustrate the Dunning-Kruger effect, a cognitive bias where those with little education on a topic actually rate their own understanding of the evidence higher than average. This comes across clearly in antivaccination arguments, where advocates project absolute certainty in their beliefs. Public health advocates and vaccine supporters, who understand the data and the evidence, may in fact seem more tentative, given the imperative to be accurate in their responses. This argument also seems to be used by alternative health providers (e.g., homeopaths, naturopaths, and chiropractors) with antivaccine roots that may not promote science-based perspectives on vaccines.
Further reading: A black hole of antivaccine misinformation (Respectful Insolence), Alternative Vaccination Schedules (Science-Based Medicine), Pseudo-expertise versus science-based medicine (Science-Based Medicine), Nine Questions, Nine Answers (Science-Based Medicine)
There are at least 14 antivaccine tropes which continue to be used in antivaccine arguments. More likely exist, but this covers the most common ones encountered. One of the most effective ways to combat antivaccinationism is to identify and to call out tropes when you see them. Don’t debate them: Pseudoscience and logical fallacies are not a serious argument against the established scientific evidence. That evidence is clear: There is no credible evidence to suggest vaccines cause autism, or that the risks of vaccines outweigh the benefits of vaccination in most circumstances. Antivaccinationists have been dodging the facts, and offering tropes instead of evidence to support their arguments for over 100 years. It’s time to stop this threat to public health.
Kata A (2011). Anti-vaccine activists, Web 2.0, and the postmodern paradigm – An overview of tactics and tropes used online by the anti-vaccination movement. Vaccine PMID: 22172504