Want to know what empirically *informed* vaccine risk communication looks like?

Drawing on material from the CCP Vaccine Risk and Ad Hoc Risk Communication study, the last few posts reported experimental results on the potentially deleterious effects of empirically uniformed risk communication.

By “empirically uninformed risk communication,” I mean to refer to information that accurately conveys the safety and efficacy of vaccines but that embeds that information in mischaracterizations of the extent, nature and consequences of public hostility to universal childhood immunization.  Ad hoc risk communication of this sort—which abounds in the media and on the internet—itself can produce misunderstandings that undermine the motivation to cooperate with universal immunization programs and that drag childhood vaccinations into the reason-effacing maelstrom of cultural conflict (Kahan 2013).

What’s more, this style of risk communication distracts those who want to promote public understanding of vaccine safety from the need to perfect empirically informed strategies for achieving this critical goal.

Such research is well underway.

As discussed in the Report, it consists not in general public opinion surveying: opinion polls lack sufficient discernment to identify the sources and mechanisms of genuine vaccine hesitancy in the public, and are not a reliable or valid measure of vaccine behavior by parents.

The most valuable research now being conducted on vaccine hesitancy uses focused and fine-grained methods tied to actual behavior.

Dr. Douglas Opel and his collaborators (2011a, 2011b, 2013), e.g., have devised—and are refining—an attitudinal screening instrument that can be used to predict parents’ willingness to obtain timely vaccinations for their children.  Such a screening device would be comparable to ones used in diverse fields from credit assessment (e.g., Klinger, Khwaja & Lamonte 2013) to organizational staffing (e.g., Ones et al. 2007), not to mention to ones used to predict or diagnose disease vulnerability (e.g., Wilkins et al. 2013).

If perfected, such an instrument could be used by physicians to identify genuinely vaccine-hesitant parents, by public health administrators to detect local pockets of under-vaccination that pose a genuine public health threat, and by researchers to develop genuinely effective risk communication materials (Sadaf et al. 2013; Opel et al. 2012)—ones that can convey factually accurate information to the right people and avoid all the hazards associated with blunderbuss, empirically uninformed ad hoc risk communication.

Of course, the public health risks posed by local enclaves of under-vaccination, as well as by misinformers who sow unfounded anxiety in these and other communities, are ones that merit response right now.

The public health establishment doesn’t have as much evidence as it needs to address these dangers as effectively as it could.

But as such evidence is being developed by valid empirical research, those who favor universal childhood immunization should make intelligent use of the currently best available evidence to promote constructive and open-minded public engagement with valid information on vaccine risks and benefits.

If you want an example, I urge you to read this excellent essay from Moms Who Vax:

It may surprise you to know that the anti-vaccine movement has long claimed to speak for parents in this country when it comes to vaccines. And it is because they are so vocal and we are so, well, busy living our lives, that legislators, government officials, and even some public health organizations think that anti-vaccine activists who believe the MMR causes autism and that the decline of vaccine-preventable disease is due to “better hygiene” represent parents as a whole, when it comes to immunization in this country.

The vast–vast–majority of us choose to vaccinate our children for two reasons: one, we don’t want our children to suffer from a preventable disease, possibly become seriously ill, or even die; and two, we don’t want any of those things to happen to our neighbors either. Here’s the problem: we don’t talk about it. I suspect this is because we consider it commonsense. One mother on this blog wrote a post titled: “There’s an Anti-Vaccine Movement?” because it had never occurred to her before she had children that people would willingly forgo something that has nearly eliminated one of the most dreaded diseases in human history (polio) and saved the lives of countless children and adults from other diseases that, if not kept in check by widespread immunization, cause unimaginable amounts of suffering.

We never thought we’d have to advocate for something that saves lives, especially the lives of children.

But here we are, and our complacency and our silence has allowed a fringe minority to sit at the table of public health in our place. And there are now consequences for our silence.

If I sound a little more passionate than usual, it’s because I’m angry. We must rise up as a group and take back the conversation. … Right now, there are legislators in Oregon who believe that millions of parents do not believe in vaccination…. Let’s prove them wrong. … Let’s do this–let’s go letter for letter, and beyond. Let’s make sure the people who make our immunization law know that we are here, that we care, that we are the 95%.

In addition to being much more eloquent and inspiring than the boilerplate “growing crisis of confidence” and “creeping anti-science” tropes that dominate ad hoc risk communication, this essay brilliantly exploits dynamics that a reflective communicator would surmise are important based on existing, evidence-based understandings of science communication:

  • Because individuals (quite sensibly!) form their assessments of risk by observing how others who are like situated are responding (Kasperson et al. 1988), the (clear, unassailablefact that the “vast majority” of U.S. parents arrange for their children to receive all recommended immunizations is itself an important and effective piece of evidence to communicate to parents—many of whom are likely to become fearful if bombarded by thoughtless repetition of the false message that an “epidemic of fear” has led to an “erosion in immunization rates.”
  • Similarly, people tend to contribute voluntarily to collective goods when they perceive that others are doing so but to refrain when they think that others are shirking or free-riding (Bowles & Gintis 2013).  So again, the message here—“we are the 95%” who contribute—is spot on.  It reinforces reciprocal motivations to contribute to the collective good of herd immunity (Hershey et al. 1994) rather than undermines them, as empirically uninformed risk communicators do by proclaiming—falsely—that a “large and growing number” of “otherwise mainstream parents” are refusing to vaccinate their children.
  • The communication manifests the willingness of the vast majority who are contributing to the public good of herd immunity to contribute to another: condemnation of the few who are free-riding. Experimental behavioral economics shows that individuals are most likely to converge on and stick to a high-cooperation equilibrium in a collective action setting when they can observe that other individuals are moved voluntarily to accept the burden of informally punishing (e.g., by shaming) the relatively few selfish actors who free-ride.  In contrast, demands for increased, centrally administered formal punishments can vitiate reciprocal motivations by convey an expectation that the disposition to voluntarily comply is lower than it actually is (Kahan 2004)—another of the many sources of scientific insight that empirically uninformed risk communicators ignore.
  • Finally, this essay is inspiringly inclusive.  It doesn’t use the cheap trick of ramping up one cultural group’s indignation by attributing socially undesirable behavior to a competing one. Characteristic of communications that—again, falsely—attribute vaccine hesitancy to one or another recognizable cultural or political group, this style of advocacy is what threatens to envelop childhood vaccines in exactly the same forms of persistent cultural conflict that inhibit public recognition of the best available evidence on myriad issues—from climate change to nuclear power to the HPV vaccine.

We need to acquire more valid empirical evidence on how to communicate vaccine risks and benefits.

But we also need to act in an informed way in the meantime.

Another of the many defects of empirically uninformed vaccine risk communication is that it diverts attention away from the most instructive and inspiring examples of how public-spirited citizens and scientists are pursuing these objectives.


Bowles, S. & Gintis, H. A cooperative species : Human reciprocity and its evolution (Princeton University Press, Princeton, 2013).

Hershey, J.C., Asch, D.A., Thumasathit, T., Meszaros, J. & Waters, V.V. The roles of altruism, free riding, and bandwagoning in vaccination decisions. Organ Behav Hum Dec 59, 177-187 (1994).

Kahan, D.M. The Logic of Reciprocity. in Moral Sentiments and Material Interests: The Foundation of Cooperation in Economic Life (ed. H. Gintis, S. Bowler & E. Fehr) 339-378 (MIT Univ. Press, Cambridge, MA, 2004).

Kahan, D.M. A risky science communication environment for vaccines. Science 342, 53-54 (2013).

Kasperson, R.E., et al. The Social Amplification of Risk: A Conceptual Framework. Risk Analysis 8, 177-187 (1988).

Klinger, B., Khwaja, A. & LaMonte, J. Improving credit risk analysis with psychometrics in Peru. (Inter-American Development Bank, 2013).

Ones, D.S., Dilchert, S., Viswesvaran, C. & Judge, T.A. In support of personality assessment in organizational settings. Personnel Psychology 60, 995-1027 (2007).

Opel, D.J., Mangione-Smith, R., Taylor, J.A., Korfiatis, C., Wiese, C., Catz, S. & Martin, D.P. Development of a survey to identify vaccine-hesitant parents: The parent attitudes about childhood vaccines survey. Human Vaccines 7, 419-425 (2011a).

Opel, D.J., Robinson, J.D., Heritage, J., Korfiatis, C., Taylor, J.A. & Mangione-Smith, R. Characterizing providers’ immunization communication practices during health supervision visits with vaccine-hesitant parents: A pilot study. Vaccine 30, 1269-1275 (2012).

Opel, D.J., Taylor, J.A., Mangione-Smith, R., Solomon, C., Zhao, C., Catz, S. & Martin, D. Validity and reliability of a survey to identify vaccine-hesitant parents. Vaccine 29, 6598-6605 (2011b).

Opel, D.J., Taylor, J.A., Zhou, C., Catz, S., Myaing, M. & Mangione-Smith, R. The relationship between parent attitudes about childhood vaccines survey scores and future child immunization status: A validation study. JAMA pediatrics 167, 1065-1071 (2013)

Sadaf, A., Richards, J.L., Glanz, J., Salmon, D.A. & Omer, S.B. A Systematic Review of Interventions for Reducing Parental Vaccine Refusal and Vaccine Hesitancy. Vaccine 31, 4293-4304 (2013)

Wilkins, C.H., Roe, C.M., Morris, J.C. & Galvin, J.E. Mild physical impairment predicts future diagnosis of dementia of the Alzheimer’s type. Journal of the American Geriatrics Society 61, 1055-1059 (2013).

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