A first-of-its-kind analysis of more than 1300 Facebook pages with nearly 100 million followers has produced a network map that’s alarming public health professionals. Antivaccine pages have fewer followers than pro-vaccine pages but are more numerous, faster growing, and increasingly more connected to undecided pages, the study finds. If the current trends continue, the researchers predict, antivaccine views will dominate online discussion in 10 years—a time when a future vaccine against COVID-19 may be critical to public health.
“The reds are winning,” says anthropologist Heidi Larson, who directs the Vaccine Confidence Project at the London School of Hygiene & Tropical Medicine, referring to the color of antivaccine Facebook pages on the new paper’s map. “They are covering a lot more ground with fewer of them.”
The online pages are “a battle for hearts and minds, and there was no map of that battlefield at the system level,” says first author Neil Johnson, a data scientist at George Washington University who previously mapped the online behavior of hate groups and the Islamic State group. “We set out to take a look at that. And we were shocked.”
For their study, Johnson and his colleagues first identified Facebook pages as pro- or antivaccine based on their content. They further identified engaged but undecided pages by their content or by the fact that the administrators of the pages had “liked,” or been “liked” by, pro- or antivaccine pages. They found 124 pro-vaccine pages, such as the Bill & Melinda Gates Foundation, with a combined total of 6.9 million followers. They found 317 antivaccine pages, such as RAGE Against the Vaccines, with a total of 4.2 million followers. And they identified 885 pages, such as Breastfeeding Moms in KY, with 74.1 million followers.
The researchers next counted each page’s links to other vaccine-discussing pages, and those pages’ links to still others, a method called snowball sampling. A software program turned the data into a map in which pages are represented as circular nodes, sized proportionally to their number of followers and represented as red (antivaccine), blue (pro-vaccine), or green (undecided). Highly connected nodes occupy more central places on the map.
The map shows many central red nodes intensely interacting with many greens. A smaller number of blue nodes interact with greens at a peripheral nexus removed from the central “battlefield,” as the researchers call it in this week’s issue of Nature. The analysis found that antivaccination pages are both locally and globally connected, whereas pro-vaccine pages are largely global or national.
In percentage terms, red pages grew their follower numbers notably more than did blue pages during the study period of February to October 2019, which coincided with a global measles outbreak. Red pages’ connectedness and influence also grew more than those of blue pages. (Total followers of all pages have since grown by millions.)
“The blues are fighting in the wrong place, they are off to one side and the main activity is around the reds which are absolutely entangled with this whole slew of green communities,” Johnson says.
Blue and red pages also engage followers differently, says Larson, who was not part of the research. Pro-vaccine groups impart information on one theme with one goal: getting people vaccinated, she notes. By contrast, the study found that antivaccine groups comprise multiple smaller groups discussing a wide range of health and safety topics. That makes them more responsive to diverse concerns and makes undecided people feel listened to, Larson says. “It’s like we as a public health community still have the old IBM model and not the startup Silicon Valley approach. … The reds have got that down.”
Pro-vaccine pages “seem to be in an echo chamber and their preaching doesn’t seem to go any further than the choir,” agrees Bruce Gellin, president of global immunization at the Sabin Vaccine Institute.
Sinan Aral, an econometrician at the Massachusetts Institute of Technology who has mapped the online spread of misinformation, praises the analysis’s large size. But he advises a “skeptical eye.” He says it’s not clear that a green page’s linking to a red page leads to persuasion or that online interactions trigger actual changes in vaccination. He adds that the predicted online dominance of red groups in 10 years “is extrapolating a lot from … limited data.”
The study only looks at how people’s views circulate, not the content of pages, “as if people don’t have reasons for their views and are only being manipulated,” says another critic, Bernice Hausman, a cultural theorist at Pennsylvania State University College of Medicine. She calls the paper’s battlefield rhetoric “troublesome,” arguing that it betrays the very mindset—casting vaccine resisters as the enemy—that turns the vaccine skeptical away.
But Johnson stands by his terminology. He concedes that the map is a first, imperfect attempt, but says, “Because we are looking at the system level, the main results of our study are robust.”