Logical Fallacies in the Vaccination Debate


The debate over vaccines is heating up recently and I’ve been shocked to see all the illogical arguments made in the conversation. Sure there are fallacies from the skeptical crowd, but it seems there are exponentially more from the proponents of vaccines. If you even dare to express doubt over the efficacy or validity of any vaccine, you’re labeled a denier on par with those who reject historical evidence of the holocaust. It’s getting out of control.

My wife and I are still investigating each vaccine and determining whether we will get them. In the meantime, I’m compiling a list of the logical fallacies I’ve encountered during this process. Enjoy:

1. “All vaccines…”

Lumping all vaccines together and saying simply “Vaccines work” is the part to whole fallacy—it’s like lumping all pharmaceuticals together and saying flatly that “pharmaceuticals work”. Yes, the theory of vaccinations (introducing certain virus- or bacteria-related pathogens into the body encourages an immune reaction that helps prevent infection) is valid. But there are four different types of vaccines: 1) polysaccharide conjugate vaccine that uses harmless parts of a bacteria, 2) attenuated (live) virus vaccines, 3) inactivated (dead) virus vaccine, 4) recombinant vaccine that uses re-engineered proteins. The polio and injected flu vaccines are composed of inactivated virus. The measles mumps and rubella (MMR) vaccine, on the other hand, is composed of living virus.

Some vaccines work; some don’t. Some cause severe side effects; some don’t. Today’s polio vaccine is fairly harmless but the first hundreds of thousands of doses proved to be defective and led to 40,000 cases of polio, leaving 200 children with varying degrees of paralysis and killing 10. The early polio vaccines also included a strain of simian virus that led to a dramatic increase in soft-tissue cancer in the subsequent decades.

Saying you’re either for or against vaccines is a false dichotomy fallacy and treating all vaccines the same is a logical fallacy and a potentially deadly one at that.

10959626_1036727693009368_2206586387077764652_n2. “Science says vaccines are effective.”

No, science doesn’t say anything. Science isn’t a unified body that has one voice and it is unscientific to believe any one scientist simply because he’s a scientist. Do your own research and come to your own conclusions. This is appeal to authority.

3. “Do it for Jack and Clio!”

Have you heard about Jack and Clio? Two poor little kids suffering from leukemia who might get measles because their immune systems are compromised so they can’t get the vaccine. It’s a heartbreaking story and something that you can’t forget, but using it as a reason to vaccinate is a fallacy called appeal to emotion. A similarly tragic story (and one that is equally illogical as a proof) is that of a young girl named Chloe who came into the hospital with Guillain-Barré syndrome symptoms in which her body was slowly becoming paralyzed. Guillain-Barré syndrome is a known side effect of the flu vaccine, which Chloe had received just two weeks before showing signs for Guillain-Barré. There are real side effects from vaccines that effect real people. Focusing on the sad stories of kids with leukemia not logical.

4. “The President wants you to vaccinate!”

A Huffington Post article recently led with the lame proof of the soundness of vaccines, “Even President Obama has urged parents to have their kids vaccinated.” This ridiculous argument is appeal to authority, and not a very convincing authority at that.

5. “…”

A couple children get encephalopathy every year from the MMR vaccine and 1 in 3000 doses leads to seizures. There are other neurological conditions that result from MMR: mental regression/retardation, motor and sensory deficits, and movement disorders and about 1 child dies every two years from it (“Pediatrics” 1998). The flu vaccine has a high incidence rate of Guillain-Barré paralysis and it has also been shown that the HPV vaccine has led to death. There have also been studies linking increased vaccination dosage with infant hospitalization and mortality. The national Vaccine Adverse Event Reporting System (VAERS) takes over 11,000 reports of vaccine injury every year, 2 percent of which result in death.

When you tell people there are real risks associated with vaccines they are silent on the subject. This is avoiding the question and is a logical fallacy.

6. “Anyone can get it!”

Claiming that anyone can get the disease that a particular vaccine guards against is appeal to fear. In most cases, only people with compromised immune systems, the young and elderly, and/or sexually active people can contract certain communicable diseases. Learn the risk factors and vaccinate accordingly.

7. “There are some pretty dumb people out there…”

Calling someone names is a version of ad hominem and associating reasonable people with common-sense objections to some vaccines with crazy “anti-vaxxers” is the guilt by association fallacy. Just because I recognize the very real risks to vaccinating children, doesn’t mean that I believe that the government is trying to make everyone autistic.

8. “There is no conspiracy theory to make your kid have autism!”

This hyperbole is a very common form of the straw man fallacy. It’s easy to reject a straw man argument out of hand. It takes a thoughtful person to address real objections to vaccines. I don’t think there is a link between MMR and autism, but there are real medical risks in taking the vaccine (see above). Dismissing the straw man doesn’t address the real issue.

9. “Andrew Wakefield was involved in shady business, so his theory is incorrect.”

Andrew Wakefield conducted a study that linked the MMR vaccine and autism in 1998. People claim that since Wakefield “paid kids for blood samples at his son’s birthday party” and “filed a patent for his own version of the MMR vaccine” that his theory is wrong. His study was retracted, but saying he was wrong because of character flaws is the genetic fallacy. An incompetent history WWII teacher doesn’t mean that WWII didn’t happen Continue Reading. What’s more important is that Wakefield and his colleague were exonerated on all charges of professional misconduct and the The Lancet has acknowledged that though they have yet to republish the paper (I can’t imagine why).

10. Changing the goalposts

A recent discussion I’ve had went something like this: “You don’t cite numbers when you speak of vaccine injury because it’s bad for your argument.” I reply that I do cite numbers (eg initial polio vaccine injury, VAERS reports cited above). “But you can’t use those numbers because vaccines are different now and anyone can make a VAERS report.” Basically, this person set a standard, which the opposing argument had failed in his mind. When it became clear that that standard had actually been met, he changed the standard. In the case of the VAERS standard, he set to make it impossible to meet at all. Since VAERS is the only official vaccine injury reporting system in the US by federal mandate, there is no other way to access data. saying we can’t use that data is like saying you can’t use any medical database on cancer, so cancer doesn’t exist.

11. Get F*ing Vaccinated!

I can use four-letter words so I must be right! This is appeal to fear. This is a very funny video about the vaccine debate. See if you can identify all the logical fallacies in it!


The stakes are certainly high. We don’t want to let the communicable diseases so prevalent in previous centuries come roaring back. But we also shouldn’t forgo logic in exchange for a sense of medical security. Do your own research (I recommend “The Vaccine Book” by Dr. Sears), and by all means, stay logical!



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