It is a curious fact, seldom remarked upon, that all diseases purportedly caused by vaccination share certain common characteristics. Chief among these characteristics is that the cause of the disease purportedly caused by vaccination is presently unknown.

Vaccine rejectionists never claim that a particular vaccine causes heart disease, gall bladder disease, bone abnormalities or any of the myriad diseases for which causes are already known. Vaccine rejectionists always insist that vaccines cause autism, vague “damage to the immune system” or unspecified neurologic injury.

The characteristics of the vaccines themselves may vary (live attenuated, killed), the route of administration may vary (oral, injection), the characteristics of the diseases that they are designed to prevent may vary (everything from smallpox, to polio, to pertussis), but the characteristics of the diseases they supposedly cause are always the same.

Even the purported active agent may vary. The harmful ingredient might be the vaccine itself, the preservative, a contaminant, combinations of vaccines, the list is endless. But the purported harms always idiopathic, are particular dreaded, are typically diagnosed within years of childhood vaccinations, and are perceived to be on the increase.

In All manner of ills: The features of serious diseases attributed to vaccination, authors Leask, Chapman and Robbins explain:

The anti-vaccination movement claim many negative consequences from vaccination. High profile controversies have promoted hypotheses that vaccines were responsible for serious and dreaded diseases or disabilities with uncertain causes. Examples include encephalopathy from the pertussis vaccine in the UK in the 1970s and, more recently in the UK, autism from the measles-mumps-rubella (MMR) vaccine and, in France, multiple sclerosis from the hepatitis B vaccine…

Parental anxieties about fearful, mysterious diseases that threaten children foment receptive audiences for such claims. These causal attributions do not rely on the strength of evidence for asserting causal association but share a number of epidemiological and societal features in addition to the uncertain or idiopathic origin of the named diseases…

What are these characteristics?

Idiopathic nature (unknown cause):

Anti-vaccination writings tend to attribute causal connections between vaccination and diseases with idiopathic origin. Autism, asthma, multiple sclerosis, cancers, diabetes and Gulf War Syndrome have all baffled science and draw intense media interest when new claims about their origin arise. Their power comes from the suggestion that danger lurks in the familiar, with the sub-text that vaccines are modern day Trojan horses, promising prevention but disguising hidden threats.

Apparent rise in incidence:

Along with having idiopathic origin, diseases like autism and asthma appear to have increased in incidence in recent decades. Anti-vaccinationists allege this increase coincides with more vaccination.

… [C]onditions like autism lack concrete biochemical or clinical parameters, making them more prone to shifts in diagnostic criteria. The ongoing reappraisal of the diagnostic criteria for the autistic spectrum of disorders over recent decades has led to substantial uncertainty over whether a true increase in incidence exists or whether such diagnostic shifts represent an artifactual increase.

Dreaded outcomes:

Many of the ills attributed to vaccination have lethal, insidious or dreaded consequences. SIDS, autoimmune disorders and developmental disability are a few examples. Such qualitative components of dreaded diseases reduce the acceptability of even minute risks. Anti-vaccine groups or individuals appear to select fearful diseases for attribution to vaccines because of the potential impact of these messages. Dreaded diseases attract news media attention thus increasing the opportunity for the amplifications of the claims…

Temporal relationship to vaccination:

Some of the diseases most often attributed to vaccines become apparent in early childhood when many vaccines are given. In such cases, parents understandably search for an agent of blame, scouring their memories for events shortly before the illness. When parents apply post hoc ergo propter hoc (after therefore because of) reasoning, vaccination can become a compelling causal candidate. Reassurances exonerating vaccines are often met with dismay by those committed to their theory. For parents who may feel guilt, albeit unwarranted, about their child’s problem, vaccination is a graspable external cause…

These features are intuitively appealing to vaccine rejectionists because they do not rely on scientific understanding, but appeal to “common sense.” In the words of sociologist Peter Bearman, writing in the recent issue of Social Psychology Quarterly (Just-so Stories: Vaccines, Autism, and the Single-bullet Disorder), vaccine rejectionists tell “just so stories,” stories with simple explanations for complex phenomena.

This explains in part why theories of vaccine rejectionism are evidence-resistant. It seems not to matter how many studies disprove the purported link between vaccines and diseases like autism. Autism is a dread disease, with unknown and complex causes and an apparently rising incidence. It is far more reassuring to pretend that autism has a simple and easily addressed cause, than to acknowledge that it can strike any child, cannot be prevented and cannot be cured.

These findings have implications for the way in which we as a society address vaccine rejectionism. The most straightforward course is to provide more education on vaccination and the science underlying vaccination. When people truly understand immunology, they do not invoke spurious relationships between vaccines and dread diseases.

Unfortunately, not everyone will respond to scientific information. Given the seductive nature of vaccine rejectionism, physicians and public health officials should also address the underlying errors of thought that occur among vaccine rejectionists. Complex diseases do not have simple causes, just because the incidence of a disease is rising and vaccination has risen does not mean that vaccines cause autism, just because a disease is diagnosed after vaccination does not mean that vaccination caused the disease.

Vaccine rejectionists need to heed H.L. Menken’s famous dictum: For every complex problem there is an answer that is clear, simple, and wrong.

For the complex problem of autism and similar diseases, vaccination is the answer that is clear, simple … and tragically wrong.

Amy Tuteur is an obstetrician-gynecologist who blogs at The Skeptical OB.

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