Tuesday, 2 November 2010

The Consequences of Anti-Vaccination

Housekeeping: This morning, I sorted out the jump break function on this site, which makes me very happy. It means less clutter/verbiage on the blog home page.

The Consequences of Anti-Vaccination

As described yesterday, today's topic is the consequences of taking a position of anti-vaccination, which actively discourages people from vaccinating and/or advocates against status quo mass vaccination policies.

Anti-vaccine activism leads to a constellation of negative consequences which can be divided into three categories: deterioration of scientific inquiry, socioeconomic harm, and deterioration of ethical behaviour.

Deterioration of Scientific Inquiry

Anti-vaccine activism degrades the quality of ongoing research in medicine (and especially with regards to vaccines and to autism - which I will touch on in a later post). It seems to me that this degradation is a three-fold process: the lowering of overall levels of scientific literacy, the diversion of limited research resources, and the promotion of science denialism.

Scientific Literacy
I would think it is self-evident that the science supporting the use of vaccines as an aid to developing adaptive immunity against infectious pathogens is fairly solid. After all, whither smallpox?

Put in more rigorous terms, without a testable hypothesis on adaptive immune function, Edward Jenner could not have proposed cowpox inoculation as a defence against smallpox. Without a testable hypothesis on antigen presentation, it would not be possible for some of the contemporary vaccines to work. And yet these hypotheses have been validated by the empirical evidence.

Indeed, one can even see immune system cells, and the microbes they attack, under a microscope.

To adopt an anti-vaccine position, therefore, is to downplay or ignore the evidence for the usefulness of vaccines, even to the point of rubbishing the existing science.

In case you think no one ever adopts this viewpoint, please read the comments of the reader handled 'Th1Th2' on yesterday's 'Vaccine Awareness Week' post on Science-Based Medicine. This commenter's contributions to almost every post on that blog on vaccines display a lamentable ignorance of adaptive immunity.

More typically, anti-vaccine activists will consistently make basic errors of fact regarding vaccines and vaccination, errors which persist despite repeated attempts to correct them by critics. Perhaps the most common error is the claim that vaccines are injected directly into the bloodstream (as I noted yesterday, they aren't). Other common, very basic errors anti-vaccine activists tend to rehash are allegations regarding the ingredients of vaccines.

The general reader may wonder why impacts on scientific literacy are particularly important - after all, it's not like everyone is all that scientifically literate. The answer is two-fold: first, anti-vaccinationism propagates scientific illiteracy, and second, I would argue that if you are going to agitate against a policy that is based on existing scientific knowledge, then it behooves you to know what you are talking about.

Impact on Research
Anti-vaccine activism diverts and subverts ongoing research.

Anti-vaccine activists often claim that vaccines (whether in general or specific vaccines) cause particular harms (such as autism - more on that later) or even lead to vague health effects based on nebulous claims of toxicity.

On occasion, these claims lead to serious research efforts, above and beyond normal surveillance, to determine their validity. Given that there are only limited resources (in terms of time, effort, and funds) for medical research, implausible claims of harm by anti-vaccinationists divert research down unproductive channels, postponing more worthy lines of research. Perversely, if researchers focus on anti-vaccinationist claims of harm, they may fail to research and detect actual adverse effects from vaccines.

Anti-vaccine activists advocate for and participate in pseudo-research, which subverts or ignores the ethics and moethods of conventional medical research.

A father-son team of anti-vaccinationists and medical quacks, the Geiers, are well-known for subverting research. They also perverted research ethics by creating their own institutional review board (IRB) to approve their research on humans.

Over the last few years, anti-vaccinationists have been holding up as evidence of their claims some studies on monkeys (such as this one). Critics of the anti-vaccine movement have pointed out some of the flaws in these studies.

One of the most important studies in the anti-vaccine research arsenal was a 1998 paper by an Andrew Wakefield, published in the prestigious British journal The Lancet. After it came out that Wakefield was, in effect, engaged in scientific fraud, the paper was eventually retracted (you can read the whole thing here).

Finally, one common request by anti-vaccination activists is for a study of the outcomes of vaccinated vs. non-vaccinated children. There are, however, compelling reasons to suggest that this would be both unfeasible and unethical.

Science Denialism
The final impact on scientific research engendered by anti-vaccination that I wish to touch on is the phenomenon of science denialism. However well-intentioned, or sincere anti-vaccine activists are, if they are going to continue to publicly pursue discouraging others from vaccinating and/or abolishing mass/mandatory vaccination programmes, they will usually be compelled to turn to denialism to maintain their position in the face of contrary evidence.

Put simply, denialism is more than mere skepticism, doubt, or even denial. Denialism is a systematic distortion and/or misrepresentation of an existing body of evidence in order to argue against the conclusions inferred from that evidence or to delegitimize particular people or policy proposals.

Some examples of denialism in action include HIV/AIDS denialism (that is, claiming that AIDS is not caused by humman immunodeficiency virus), 9/11 "Truth" (the claim that a conspiracy, centred around the George W. Bush administration, devised a scheme to undertake the terror attacks of September 11, 2001), Obama birth denialism (the claim that current US President Barack Obama is not a US citizen by birth, and therefore is ineligible to hold the office of President), and the bête noir of denialisms, Holocaust denialism (the claim that the systematic murder by Nazi German authorities of Jews during the Second World War either did not happen or was grossly exaggerated).

Denialists, whatever their topic, tend to support their claims in remarkably consistent ways (South African judge Edwin Cameron points out here the commonality between the methods of AIDS/HIV and Holocaust denialists), which I will not go into great detail here (sorry).

Denialism regarding vaccines involves using fallacious logic and rhetoric and distorting or misrepresenting the current body of evidence while arguing any (or all) of the following:
  1. Vaccines are/were not nearly as effective as conventionally believed (a variant of this is that vaccine-preventable diseases were "on the way out", so to speak, before mass vaccinations);
  2. Vaccines cause adverse effects at rates far beyond what is currently recognized (or, alternatively, that adverse effects from vaccines are in some respect 'worse' than other medical adverse effects or causes of injury);
  3. The diseases that vaccines prevent are simply not as serious as once claimed (or that modern medicine can effectively treat them and vaccination is not useful).

As an aside, most people will object to being referred to as denialists, on the grounds that the application of that label is a way of arguing guilt by association or an argumentatum ad Hitlerum (given the association of denialism with Holocaust denialism). It is important to understand that calling a particular position 'denialism' does not actually have anything to do with the motives or morals of the people espousing that position, and everything to do with the techniques they use to support it, techniques which the various forms of denialism have in common. It is also worth pointing out that denialism vis-à-vis infectious diseases certainly involves arguing against the evidence of far more deaths than Hitler et al. ever managed.
Influenza from the 1918 pandemic. That Hitler chap is a rank amateur compared to these little fellows and their friends.

Socioeconomic Harm

Perhaps the most pervasive consequence of anti-vaccine activism is waste. As described above, anti-vaccine activism can lead to misuse of limited research funds, time, and effort attempting to find evidence of generic or specific problems with vaccines.

Anti-vaccine groups and individuals can (and do) clog up the legal system with tort cases (more on this below), and indeed, they nearly chased pharmaceutical companies out of the vaccine manufacturing business in the '80s (hence the creation of the NVICP in the US). In that respect, there is a waste of legal resources (and a lot of money spent on lawyers that could have been spent elsewhere).

Finally, if vaccination rates declined enough or mass vaccination was abandoned, the incidence of vaccine-preventable diseases (and predictable complications) would naturally increase as they came back into general circulation. Please take a moment here to consider the costs involved in visiting a hospital for care when you have, say, measles encephalitis, or pneumonia from pertussis, or have to go into an iron lung for polio. Consider also the costs to parents who have to take time off work to care for their sick children, and the costs to parents' employers (or employees - bosses have kids too). Consider also the opportunity costs involved: using up hospital space for vaccine-preventable diseases denies its use for other purposes, to say nothing of the potential increase in hospital-acquired infections.

This last set of socioeconomic harms is a particularly perverse consequence when considering the anti-vaccine position. Many anti-vaccine activists allege that doctors and pharmaceutical companies recommend vaccination to boost their profits. However, many doctors (particularly those specialized in infectious diseases) would surely make more money if vaccination halted (money quote from Dr. Mark Crislip's post on Science-Based Medicine: "I make, or made, a large chunk of mortgage payment from hospital acquired infections. Not any more."). Similarly, many companies that produce vaccines also produce medical supplies (antibiotics, machinery, etc.) that would be used in increasing amounts in the case of widespread disease circulation (to say nothing of other medical supply companies which are not also pharmaceutical/vaccine producers). See, for example, an in-depth analysis here (the author only has detailed numbers up for diptheria and pertussis at the moment, but I think that is enough for you to get the point).

Spread of Infectious Disease
Anti-vaccine activism directly increases the spread of infectious diseases in two ways: clustering, and general reduction in vaccine uptake.

As any group sharing like interests, philosophical outlooks, or other commonalities, anti-vaccine activists tend to band together. There is, of course, nothing morally wrong with doing so. But since anti-vaccinationists tend to either not be vaccinated (rarely) or not to have vaccinated their children (more common), their gatherings run a higher than usual risk of being vectors for disease transmission, and can maintain disease circulation even when the wider community has vaccine uptake rates that would normally be high enough to achieve herd immunity.

Reduction in Vaccine Uptake
When people are exposed to anti-vaccine arguments, they may or may not find them persuasive. If they do, then they may also postpone or halt vaccination for themselves or their children, reducing overall vaccine uptake. If this reduction is significant enough (i.e. uptake rates fall below herd immunity levels), the consequences are predictable.

Ethical Deterioration

As I pointed out at the outset, there is nothing particularly bad or immoral about anti-vaccine activists. Most of them are convinced of their rectitude.

All the same, that does not protect them from deterioration of their ethical positions - that is, that they will not make unethical arguments or engage in unethical behaviour. I wish to highlight the most common examples here.

Anti-vaccinationists are, as pointed out earlier, often caught making basic errors of fact regarding vaccines. If they correct themselves, it is all well and good. If they repeat the same errors (whether migrating from online news story to blog post to discussion group and so forth, repeating the same errors over and over and being corrected on each in turn, or even making demonstrably false claims on the same forum repeatedly) over and over, or if they are consistently caught out making factually false claims, then it is time to question their honesty regarding vaccines.

Levelling Down
Since the majority of public health officials and scientific experts in relevant fields (epidemiology, infectious disease control, pediatrics, and the like) support mass vaccination, countering this accumulated expertise requires accepting "levelling down", that is, the denial or minimization of specialized expertise in a field of human knowledge or technique, and the simultaneous upholding of casual non-experts as equals to actual experts who have spent their careers (whether spanning years or decades) delving into the available data.

Some notable examples from anti-vaccination include:
  • Jenny McCarthy, former model and actress whose son Evan is on the autism spectrum (more on the anti-vaccine-autism connection in future posts). Jenny holds herself up (and is held up by others) to be a 'mother warrior', whose admixture of cognitive biases, intuitive reasoning, and organic memory (lumped together as 'mommy instincts'), we are told, are superior to careful epidemiology and meticulous assemblage of data when evaluating such things as the safety or efficacy of vaccines or the etiology of autism.
  • Jay Gordon, MD FAAP, who is an actual pediatrician (that is, one would think he is an expert). Unfortunately, he also values personal experience (that is to say, the same quality Jenny McCarthy claims give her special insights) over rigorously-collected data. Consider this review of an open letter he published in 2008. He occasionally says as much when commenting on sites such as Respectful Insolence (money quote: "There is no proof that delaying vaccines, as I recommend, is safer, but my biased impression is that it is.").

Anti-Social Behaviour
Anti-vaccine activism can occasionally lead to anti-social behaviour. Many anti-vaccionation activists seem to possess a binary world-view when it comes to vaccines and debates over them, where their position is just and opposing positions are wicked. Between such a viewpoint and the presumption of conspiracy on the part of public health officials or vaccine manufacturers, it is easy to see how anti-vaccinationists can be led to, and justify, anti-social behaviour.

Consider the following examples:
  • Dr David Gorski of Science-Based Medicine explaining how his work online against anti-vacciationism led to false conflict-of-interest smear attempts and even an attempt to get him fired from his job.
  • Misogynist attacks on journalist Amy Wallace, who wrote an article critical of anti-vaccination for Wired magazine.
  • Age of Autism, perhaps thinking this was funny, publishing a Photoshopped scene of pro-vaccine advocates sitting down to a Thanksgiving meal of human baby (echoes of A Modest Proposal, perhaps?). The original article is gone (in Orwell-speak, one would say 'down the memory hole'), but the Internet is forever, and a screenshot lingers on.
  • Dr. Paul Offit, who specializes in vaccine research and development, has to deal with death threats to himself and his family as a matter of course.

Concluding Remarks

As we have seen, taking up the cause of anti-vaccinationism can lead to deterioration or denialism of the scientific literature on vaccines, to harmful socioeconomic consequences to both anti-vaccinationists and others, and to anti-social behaviour on the part of anti-vaccine activists in relation to their philosophical opponents.

How does one justify these consequences? I have a hard time trying to understand how anyone can be so motivated against life-saving medicine that they would, however unwittingly, bring down these problems on their own heads (to say nothing of others' heads).

Perhaps it has something to do with tomorrow's post, on double standards.

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