It’s time to talk about the anti-vaccine (or anti-vax) denialists. Considering the Autism Omnibus trial is underway to decide whether or not parents of autistic children can benefit from the vaccine-compensation program, a fund designed to compensate those who have had reactions to vaccines and shield vaccine makers from the civil suits which drove them out of the country in the early 1980s. I think it’s topical and necessary to set the record straight about vaccines, their risks, and many benefits. To do this though, we’ll have to talk about the history of and resistance to vaccination, the history of autism and the current alleged epidemic of autism, and the denialist arguments used by the anti-vaxxers to suggest that vaccines are linked to the disorder.
Since vaccination was discovered to confer immunity to individuals there has been resistance to vaccination.
Widespread vaccination began in the early 1800s following Edward Jenner’s presentation of an article to the Royal Society of London in 1796 detailing his success in preventing smallpox in 13 people by inoculation with live infectious material from the pustules or scabs of people infected with cowpox. The process induced cowpox, a mild viral disease that conferred immunity to smallpox. Jenner called the cowpox material “vaccine” (from vacca, the Latin for cow) and the process vaccination. Although Jenner did not discover vaccination, the was the first person to confer scientific status on the procedure and was chiefly responsible for popularising it.
A large number of antivaccination tracts, books, and journals appeared in the 1870s and 1880s. The journals included the AntiVaccinator (founded 1869), the National AntiCompulsory Vaccination Reporter (1874), and the Vaccination Inquirer (1879). Similar movements flourished elsewhere in Europe. In Stockholm, the majority of the population began to refuse vaccination, so that by 1872 vaccination rates in Stockholm had fallen to just over 40%, whereas they approached 90% in the rest of Sweden. Fearing a serious epidemic, the chief city physician, Dr C A Grähs, demanded stricter measures. A major epidemic in 1874 shocked the city and led to widespread vaccination and an end to further epidemics.
At the time, the anti-vaccination movement did have some legitimate arguments. This was, after all, before the germ theory of disease was understood, and vaccination was not done in a nice sterile fashion as it is now. As medical science has improved, so has the science of vaccination, and there are few public health measures that rival the success of vaccines in preventing disease. Smallpox has been eradicated. Polio, which used to sicken and paralyze thousands a year is largely eradicated. Tetanus, which still kills hundreds of thousands a year worldwide – particularly in neonates – is exceedingly rare in countries with routine vaccination – like the United States since the 1940s.
This is a terrible disease, and one that the first-world prevents (since the spores are everywhere and cannot be eradicated) through immunization.
Muscular spasms in a patient suffering from tetanus. Painting by Sir Charles Bell, 1809. From the tetanus wiki
Diptheria, pertussis, measles, mumps, rubella (which caused blindness in thousands yearly), and numerous other diseases can be prevented, and morbidity and mortality decreased through immunization. Each of these diseases still kill many hundreds of thousands a year worldwide. Vaccination programs could prevent and in some cases eradicate them if vaccination were properly invested in and pursued.
The benefits of vaccination are clear. But there is a pervasive distrust among some people of medicine, of pharmaceutical companies, and when something needs to be blamed for a child’s illness, vaccines seem to be an easy target. Especially since their benefits these days seem more abstract – people don’t see tetanus and diptheria any more, so why risk a vaccine to prevent it? And man will people blame vaccines for some crazy stuff. For instance, people who have killed their infants by shaking them have gotten anti-vaxxers to blame vaccines for their crime. It’s also not too surprising to see, when one peruses the various anti-vax sites (there are too many for me to list and the Millenium project’s list here is very thorough), the overlap with other anti-medicine movements, including HIV/AIDS denialists like Mohammed A. Al-Bayati, and various types of woo-promoters.
What is universal about the anti-vaccination sites is that they overestimate the risks of vaccination, while underestimating the benefits – or denying they are responsible for preventing disease at all. Often they will suggest a disease disappeared because of other public health measures, better hygiene etc., despite the fact that the drop off in each of these illnesses occurred immediately after the introduction of the vaccine, and these vaccines were rolled out at different times – often decades apart. They also like to point out how rare the diseases are that are being vaccinated against, and how compared to the risk of adverse events the vaccines are therefore not worth it. People may think that now that these diseases are rare that immunization might now be unnecessary. However the evidence is that when vaccines are attacked and immunizations decrease, these now-rare diseases are quite capable of making a comeback.  Further the other denialist tactics are always present. From conspiracy theories about the medical establishment hiding the truth, to cherry picking a few studies about mercury and thimerosal out of context (and ignoring the IOM reports and systematic reviews), fake experts like Mark and David Geier , to some outstanding examples of moving goalposts (like not letting go after thimerosal was removed from vaccines), to the classic logical fallacies.
But why does autism get special attention as having a link with vaccination? Specifically, why does thimerosal, the mercury-containing preservative that allows vaccines to be stored in multi-dose vials, get so much blame?
To understand this, I think a brief history of autism is also warranted. Autism was first described by Leo Kanner in 1943, then underwent the classic progression of psychiatric blame. It only took about 10 years or so for psychiatrists to start blaming the parents – specifically “refridgerator mothers” for causing the disorder. Hey, they were Freudians. They have to blame the mother first. By the 70s though, people were realizing how stupid this was and started looking for environmental and genetic causes. As parents were blamed less the disorder lost much of it’s stigma – as a diagnosis of autism essentially meant you were a bad parent in the eyes of the Freudian quacks. It kind of reminds me of the Simpson’s episode Hurricane Neddy and Dr Foster’s great line “Get down from that bookshelf, please. Most of those books haven’t been discredited yet!”
This is where the problem starts. As the disorder was recognized separately from other learning disabilities and developmental delays, parents were more interested in having the appropriate diagnosis and getting help specific to the disorder. Then critically, in the 1990s, it was added as a separate category of disability for special education. The result was far more diagnoses of autism and a decrease in diagnoses of other disabilities.
The notion that the prevalence of autism is increasing would seem to be borne out by the increasing rate seen in special education programs in the US, but that’s a fallacy according to Dr. Paul T. Shattuck.
He found that the administrative prevalence of autism rose from 0.6 cases per 1,000 students in 1994 to 3.1 cases per 1,000 students in 2003. Seventeen states reported increases in autism rates that would qualify as an epidemic.
During the same time period, the prevalence of mental retardation fell by 2.8 cases per 1,000 students and the prevalence of learning disabilities fell by 8.3 cases per 1,000 students. The increase in autism prevalence was significantly associated with declines in mental retardation and learning disabilities.
“Autism was not added as a separate category until the early 1990’s, and all newly introduced categories experience explosive growth. No one is claiming there’s an epidemic of brain injury, for instance,” Dr. Shattuck commented.
He also notes in his paper that prevalence findings from special education counts are well below epidemiological estimates for most states, and so do not support the claim of an autism epidemic.
In the broader context of widespread public concern that autism rates have been increasing sharply, and that childhood vaccinations are to be blame, Dr. Shattuck said, “I hope the article creates more informed consumers of prevalence claims. Many bright people, including doctors, have turned to the special education counts hoping to find meaningful information…in the absence of good quality surveillance data.”
Additionally the diagnosis of autism was expanded from a more limited set of criteria to a spectrum, hence the current designation of autism spectrum disorder rather than merely “autism” to describe everything from severe autism to milder versions of the disorder such as Asperger’s syndrome.
Well, the problem should now be obvious. The disease emerges from a dark period of psychological misunderstanding, and barbaric treatments, and parents, no longer stigmatized by the diagnosis, want treatments, help and education specific to their child’s disorder. Special education funding opens up, and autism diagnoses increase with concurrent decreases in other mental disorders. But outside of this context all people see is a massive increase in the rate of autism diagnosis. They naturally ask, what is causing this apparent epidemic of autism?
The anti-vaxxers, always keen to blame something new on vaccines, come to their rescue, helped along by one particular small and unreplicated study by Andrew Wakefield who has subsequently been shown to be on on the payroll of the anti-vax lawyers. Mostly, thimerosal and/or the MMR gets blamed. Then repeatedly vindicated. Thimerosal was even removed from vaccines in the United States (all but flu – thus reducing the dose about 10-fold – although there is a thimerosal-free flu shot approved for kids under 4) with no concurrent decrease in autism diagnoses – if anything they continue to increase.
Despite all of this evidence that thimerosal wasn’t the cause, the anti-vaxxers still pursue vaccines and thimerosal as a cause of autism. In the current Autism Omnibus hearings, a panel of three judges (or Special Masters) are reviewing the “expert” evidence for a link. I’ve been following the trial from the transcripts and recordings and the link still simply has no evidence. The testimony is telling. First of all, the witnesses can’t decide on the cause – thimerosal or the attenuated measles virus or both together or genetic mercury hypersensitivity etc. Day one starts with an expert who goes into all sorts of mercury poisoning with different varieties of the chemical – organic, elemental and inorganic – and completely fails to connect the disparate forms of poisoning from excess doses to anything resembling autism – especially based upon the type of mercury in thimerosal. Instead the best he can come up with is an essentially unprovable hypothesis about “brain retention” of mercuric mercury. The next couple of witnesses provide similar scant evidence, with no solid links (and some nice CV inflation along the way), and eventually jump to blaming attenuated measles virus for autism – not based on anything measles virus has ever done in humans but based on canine dystemper since it happens to be in the same family! This is the best they’ve got, and it ain’t much. No proof of causality, no isolation of mercury or measles from brain or CSF, just conjecture, speculation and circumstantial nonsense. See Autism Diva with some great coverage and Orac’s coverage of the quacks’ coverage.
The evidence is mounting that autism is primarily a genetic disorder. One obvious flaw with environmental exposure is the high predominance of autism among males vs. females. An environmental cause would likely effect both sexes equally in prepubescent children. Further it is linked to a specific genetic cause in about 10-20% of cases and this number is likely to be revised upwards. The most recent and powerful study into the genetics of autism suggests a strong correlation between copy number variation of various genes and sporadic autism spectrum disorders. While our knowledge of the cause is by no means complete, an environmental cause doesn’t fit with the basic facts.
I’ll add as a final note, one of the saddest aspects of the anti-vax intrusion into autism, aside from the usual problem of attacking such a beneficial public health measure, is the encouragement by the anti-vax quacks of human experimentation on children. Between the Defeat Autism Now doctors and quack treatments like the Geier’s bogus Lupron protocol (Lupron is a drug usually given to kids to prevent precocious puberty), the approach the anti-vaxxers advocate is usually based on the faulty premise of mercury being present in the kids. The kids are then subjected to chelation treatments meant to remove the mercury from the bloodstream – a dangerous and occasionally lethal procedure – for no good medical reason. The kids are essentially getting stuck with needles constantly, put on whatever diet the fake experts can come up with based on some tenuous hypothesis about the cause of autism, and with confirmation bias rampant – the testimonials of these unmonitored and poorly-designed experiments on children pull in more parents desperate to find anything that will make their kid normal. If it wasn’t for the parents’ active involvement in experimenting on the kids, this would be a Nuremberg violation (and should be anyway in my opinion).
Ratbag’s full list of anti-vax quacks
Robert Kennedy Jr.’s “deadly immunity” at salon.
I also include the The Huffington Post as an anti-vax denialism site. While not 100% denialist, it has an entrenched anti-vaccination element including Robert Kennedy Jr.’s BS articles and David Kirby railing against the evil mercury (should we be surprised when they give Deepak Chopra a loudspeaker?). Although it should be noted they’ve made a positive step in publishing Arthur Allen’s work recently instead.
And don’t forget to experiment on your kids with the help of DAN!
1. Robert M Wolfe, Lisa K Sharp Anti-vaccinationists past and present BMJ 2002;325:430-432.
2. EJ Gangarosa, AM Galazka, CR Wolfe, LM Phillips, RE Gangarosa, E Miller, and RT Chen Impact of anti-vaccine movements on pertussis control: the untold story The Lancet 1998; 351:356-361