During a late-night car ride through the Athens hills, I realized that a colleague of mine was vehemently opposed to vaccination. He teaches at a world-leading university and has founded a visionary company; we even live in the same tech-savvy neighborhood in California. And yet there we were: after an intense day of brainstorming with more than a thousand European innovators, he opened up to me about the terrible neurological injury that his son had suffered after a routine vaccination. In my colleague’s telling, overnight his son transformed from a charming and open boy with a sunny smile into a withdrawn, nonverbal shadow of his former self.
As a scientist, my first instinct was to counter with data, analyses, and insights from experts. About how vaccinations are possibly the single most important invention in the history of our species, having prevented hundreds of millions deaths over about 200 years, including an estimated 2 to 3 million deaths per year currently. About how vaccines are safe for the overwhelming majority of recipients. About how vaccines do not cause autism, and how after fraudulent claims in the 1990s by a man who subsequently lost his medical license, scientists around the world have doggedly sought evidence of such a link—and have repeatedly failed to find any.
Instead, I listened and asked questions. My colleague and his wife were utterly devastated, and their lives changed forever. They felt repeatedly ignored by their son’s doctors and their friends and colleagues in the medical community. In desperation, they looked online, where they discovered an international community openly discussing their experiences, sharing their opinions—and promoting answers out of line with the preponderance of biomedical evidence. He and his wife had found their tribe.
When it comes to matters of public health, “opinion” is not synonymous with “fact,” no matter how personal or deeply held the opinion. Health regulations must be made based on evidence and updated as the scientific process unfolds in order to achieve the ultimate goal of better health for all people.
Nonetheless, as the approval and deployment of vaccines against COVID-19 nears, it is essential that public trust be valued, earned, and maintained. This urgency is sharpened by the growing threat posed by misinformation (false information) and disinformation (deliberately false and misleading information), which are widely recognized as major threats to public health and to geopolitical stability.
It is tempting to fall into a “battlefield mentality” when it comes to vaccination. On one “side” there are people holding pro-vaccine positions: scientists and health professionals pointing to years of empirical data about the safety and efficacy of vaccines. This group also includes the people—hundreds of millions, even billions of them—who chose vaccination, perhaps because they trusted their governments and experts, or perhaps because vaccination was easy or mandated. On the other “side” are people holding anti-vaccination positions, including people who attribute a negative personal experience to vaccination as well as those who have been convinced by anti-vaccination messaging. And in the middle are the “undecided” or “hesitant,” who have yet to commit to a stance.
While the “battlefield mentality” has provided insights into vaccination behaviors, keeping people at the center of efforts to safeguard public health is crucial. In this article, I will shares insights from a recent peer-reviewed investigation of online interactions about vaccination and integrates these insights with an orthogonal approach to understanding vaccine hesitancy. Overall, by seeking shared language around our common goal of health, we can craft strategies for effective evidence-based health interventions.
Dynamic network infrastructure influences the flow of reliable information
As more and more worried and desperate people turn to the Internet to form opinions and decide which behaviors to enact, our overall goal should be to have the signal of reputable health information be far stronger than the noise of misinformation and disinformation across platforms and algorithms.
In June 2020, Nature published Johnson et al.’s open access, peer-reviewed, graph-theory approach to characterizing the vaccination views of nearly 100 million individuals on Facebook (out of 3 billion current Facebook users). For more information on the data, analyses, and underlying mathematics, see the Supplementary Information accompanying the main article.
At a high level this analysis revealed two crucial insights: (1) people actively seek information in order to formulate a position on vaccination, and (2) these “undecided” or “hesitant” people are quantitatively more likely to encounter anti-vaccination “clusters” (Facebook Pages) than pro-vaccination clusters.
From a more technical graph-theory perspective, cluster size (the number of people following a Facebook Page), linkages (connections between clusters), and network centrality (how connected a cluster is to other influential clusters) are important measures that change over time. Intuitively, the more links between clusters, the more information that can flow. Linkage density is also a critical consideration: if all roads lead to Rome, no matter which path you walk, you end up in the Eternal City. Since people often share mis- and disinformation without knowing that it is false, this dynamic infrastructure is key.
While the anti-vaccination clusters analyzed by Johnson et al. had fewer followers than the pro-vaccination clusters, there were more anti-vaccination clusters than pro-vaccination clusters, and the anti-vaccination clusters were more centrally located in the online ecology of vaccination views. Medium-sized anti-vaccination clusters underwent the most growth, in contrast to the “rich get richer” mentality of the network flywheel effect that has been popularized by Silicon Valley. Further, during the 2019 measles outbreak, anti-vaccination clusters more successfully increased their network centrality than pro-vaccination clusters.
Importantly, Johnson et al. found that anti-vaccination clusters employ more diversity of narrative than pro-vaccination clusters. In other words, anti-vaccination clusters more often position vaccination as part of a wider discussion involving (often “alternative”) health, safety, and even conspiracy theories. By broadening the conversation to general wellbeing, anti-vaccination clusters often effectively support diversity and inclusion; no matter your ethnicity, education level, or geographical location, you should want to keep your family healthy!
Particularly in times of crisis, the narrative diversity of anti-vaccination clusters casts a wider net than the traditional, often data-centered stories told by science and health agencies and supported by some social-media companies. This divide is particularly salient in today’s COVID-19 crisis: populations at disproportionate risk often have been failed by medical systems and governments in the past. Thus, while pro-vaccination messaging labors under the historical burden of exploitation of marginalized groups, anti-vaccination messaging is amplified by the legitimate fears of these groups and others.
Johnson et al.’s analysis of the measles outbreak of 2019 underscores that it is crucial to disseminate and support evidence-based messaging during a major public health crisis such as COVID-19. We need to foster the growth of clusters sharing reliable information as well as the linkage of these clusters to other parts of the network.
Whose job is it to carry out these interventions? There are obvious major considerations involving censorship and freedom of speech. On the one hand, social-media platforms are hosted by private companies, and there are ongoing and important conversations about the extent to which business should be disentangled from the state. On the other hand, health is a public—and therefore obviously governmental—concern.
Moral statements can reveal opportunities for connection during health interventions
When the undecided come looking for information upon which to formulate an opinion, they are not just looking for data: they are looking to connect through stories–human stories, like my colleague’s. This goal of connection at the human level is why I opened this article with my deeply personal memory about a colleague’s emotional journey regarding his son’s health.
Our responses to an issue depend strongly on how we feel. As a science communicator, I increasingly turn to Moral Foundations Theory. Briefly, this framework acknowledges that innate human intuitions cue emotional responses that can influence—often far more than we care to admit—our opinions and therefore our behaviors. In the six-foundations version of this theory, the foundations of our intuitions are care/harm, authority/subversion, loyalty/betrayal, liberty/oppression, purity/degradation, and fairness/cheating. If a statistical analysis reveals that particular foundations are influential in a given population, then messaging can be tailored to speak directly to those foundations. In a massive body of work over decades, Moral Foundations Theory has been applied to a huge spectrum of problem spaces from implicit bias to climate change to politics and beyond.
Moral Foundations Theory has also been used in several studies focused on vaccination. For example, Amin et al.’s peer-reviewed 2017 study in Nature Human Behaviour sought statistically significant connections between vaccine hesitancy and moral values in two large populations of American parents. The analysis identified two connections: to generalize, parents who were highly vaccine hesitant were influenced by beliefs that immunization “pollutes” the “pure” bodies of their children (purity/degradation) and that governments should not have the power to “control” individual behavior (authority/subversion and liberty/oppression). Interestingly, Amin el al.’s statistical analyses indicated that these associations were not affected by gender or political ideology.
Moral Foundations Theory constitutes one pathway to increase the narrative diversity, and therefore effectiveness, of messaging that supports human health. Quantitative analysis of particular populations can guide the design of effective strategies; fortunately, social media itself provides ways to gather such data before an intervention is tested and eventually rolled out. Resources are available for visual images, terminology that can be used for natural language processing and other text-based analyses, and even short vignettes.
Looking forward: Translating connection into effective health strategy
As the scientist and philosopher Donna Haraway has said, “There is a strategic use to speaking the same idiom as the people that you are sharing the room with. You craft a good-enough idiom so you can work on something together.”
In other words, by moving away from the habit of “versus,” we enable a future of “together.” As we have seen, data and architecture from digital technologies can be mindfully harnessed to foster human connections and, ultimately, to empower human-centered health interventions.
The COVID-19 pandemic is underscoring the dangers of ignoring these insights while simultaneously providing a major opportunity to accumulate the world’s most valuable commodity: trust. In my next article, we will explore strategies for building and maintaining trust, and how to enable effective human-centered health interventions beyond today’s crisis.