Disinformation in the digital world often causes significant harm in the physical world. Nowhere is this more true than in the case of the ‘anti-vaxxer’ movement. In this blog post, we explore the rise of vaccine scepticism online and how it links to broader patterns of disinforming narratives. We’ll illustrate this using examples from social media data, as well as from our data set of 20,000 websites carrying disinformation.

A major risk from the anti-vaxxer movement involves measles, one of the most infectious human diseases in existence. In recent years it has made a dramatic comeback worldwide, with cases rising to their highest level since vaccines came into widespread use. From 2016 to 2017, the World Health Organization (WHO) reported a 30% increase in measles cases. Resurgence has been linked to various factors, but the most pernicious is the emergence of a global shift towards vaccine scepticism.

One particular piece of scientific research has been widely blamed for catalysing anti-vaxxer beliefs. In 1998, Andrew Wakefield, a British medical doctor, published a paper linking the MMR (measles, mumps, rubella) vaccine to childhood autism. Wakefield’s research has since been found fraudulent and subsequently discredited. But the damage had been done; his work had already sown the seeds of a movement which eroded public confidence in the safety of vaccines.

Anti-vaxxer beliefs have their roots in flawed science, but they are fuelled by the same psychological processes that make people susceptible to other forms of disinformation, as the GDI has argued previously. Mistrust of governments, elites and experts is a recurring theme across many disinforming narratives, from flat Earthers and 9/11 sceptics to those who believe in theories of global domination by secretive cabals. Research has also shown that people who believe in these conspiracy theories are more likely to be vaccine sceptics. In free societies, people are entitled to their beliefs, but, unlike any of these other narratives, anti-vaccination disinformation has already proven its potential to cause widespread and definite harm to populations around the world.

Figure 1: Vaxxter anti-vaccination website

Figure 2: VacTruth website showing common (and discredited) narrative about vaccines causing autism

Examining social media data indicates that the online anti-vaxxer movement is picking up steam and shows no signs of abating. In Figure 3, we can see massive growth (over 252%) in page likes over the last three years, based on a dataset of 185 anti-vaxxer Facebook pages.

Figure 3: Growth in page likes over time (Source: CrowdTangle)

Sharing of content on social media has been likened to the spread of disease. It’s where the term ‘going viral’ originally comes from.

Figure 4 shows the levels of different interactions taking place on the Facebook pages over the three year period. Link sharing is the most common interaction, suggesting that anti-vaxxer content is being frequently spread from one user to another. Although our sample of Facebook pages is relatively small, the strong presence of link sharing behaviour could help explain not only the prevalence of anti-vaxxer content online but also why vaccine sceptic attitudes have begun to show distinct consequences in the offline world.

What’s more, lots of interaction with links suggests that users are likely to be clicking through to external content, such as that shown in Figures 1 and 2. Accordingly, harmful anti-vaxxer websites could be attracting significant traffic, potentially making money from hosting programmatic advertising, which could include ads for unrelated and unsuspecting brands.

Figure 4: Facebook page interactions over time (Source: CrowdTangle)

Figure 2 also demonstrates how Facebook videos are the most commonly found type of anti-vaxxer interaction, after links. Video content is far more compelling and drives better engagement than does text, according to recent research.

The spread of anti-vaxxer disinformation has already been linked to a new rise in harmful – yet easily preventable – diseases. There has been intense pressure on social media platforms to address the issue of health disinformation. Facebook is yet to announce measures to handle the problem, but other platforms, most notably Pinterest, have been more forthcoming to remove related content.

We can’t control people’s opinions, but we can help fix the system that delivers funding to anti-vaxxer websites via programmatic advertising of unsuspecting brands. By enabling ad tech firms to create better lists of disinforming sites, we can give them the choice of whether or not to serve ads to domains known for hosting anti-vaxxer messages.