Science and Politics in the Polio Vaccination Debate on Facebook: A Mixed-Methods Approach to Public Engagement in a Science-Based Dialogue

"The polio vaccination debates on Facebook are a clear example of public engagement with a scientific issue, and illustrate the ways people deploy scientific knowledge alongside other resources in the case of vaccine hesitancy..."

This study characterises public engagement with the 2013 polio crisis in Israel in a social media environment. A qualitative analysis is combined with a quantitative analysis of the characteristics of the debate on polio vaccinations in a Facebook group dedicated to parental and professional dialogue. The role of dialogue in such a space is often to build and promote trust between decision-makers and/or scientific experts and the lay public and thus could be a place to both study vaccine hesitancy and to combat it.

The context of the study is that, on May 28 2013, traces of wild polio virus (WPV) were found in the sewage system near the settlement of Rahat in the southern part of Israel. In mid-August 2013, Israel's Ministry of Health, with the encouragement of the World Health Organization (WHO), launched a full-scale vaccination campaign called "two drops". The Ministry of Health reinstated a vaccine that had been taken off the national vaccination list 8 years earlier and asked all parents to have their children vaccinated outside of the routine set of vaccinations, which prompted a wide-ranging public debate that attracted tremendous media attention. One active and diverse public-debate platform at that time was a Facebook discussion group called Parents Talk About Polio Vaccination, or Horim Medabrim al Hisun HaPolio in Hebrew. At its peak, the group had 1,741 members (November 12 2013), and a posting rate of 109 posts per day (August 21 2013). The group is no longer active, but it is the focus of the present research.

Continuing to provide background, the researchers describe vaccine hesitancy as a decision-making process that depends (among other variables) on trust in the health authorities and in mainstream medicine. The vast majority of the public are not biologists or epidemiologists, and they thus need to trust the sources that deliver the information to them and act upon guidance from these sources. This opens the door to political considerations and evaluations of the sources who deliver the information. The researchers consider "political" anything that involves power relations, including dialogue and public engagement in the scientific realm. They characterise mainstream media and social media as "among the most important and powerful agents that mediate between science and the public"; this evokes the concept of "media logic".

To collect the qualitative data, a manual search in the Facebook group Parents Talk About Polio Vaccination was carried out according to 3 main criteria: rich discussion (at least 25 comments per conversation); diverse participants (both lay and professional); and diverse views (both for and against the vaccination). Forty conversations (threads) were collected. The qualitative data were analysed thematically: The texts were tested for emerging themes, in a triple-stage refinement procedure.

The qualitative analysis of the discourse and dialogue revealed 3 major themes, which are illustrated from excerpted comments from the Facebook group:

1. The discussants in Parents Talk About Polio Vaccination adhered to the culture and conventions of the ways in which various topics are portrayed in the media, or in other words, capitulated to the biases and logic that govern the media. More specifically, discussants in the group devoted much of the dialogue to personal, unique stories. They tended to focus on the simpler aspects of conflict and drama (what the Ministry of Health was "forcing" them to do) rather than complex and elaborate explanations (such as scientific explanations). The story of the paralysed child whose paralysis had nothing to do with his polio vaccination is an example of fragmentation. This story was used repeatedly as a reason why parents should refrain from vaccinating their children, while ignoring the larger context of the story itself, as well as the larger context of the reasons why the vaccination was recommended in the first place. There was also evidence of an authority-disorder bias, which is about dealing extensively with questions of public (dis) order, and whether the authorities are capable of creating and maintaining social order.
2. The discussants displayed a fear of uncertainty, such as concern about the uncertain outcomes of the vaccination.
3. The nature of the debate in the group Parents Talk About Polio Vaccination shifted from scientific to political and ethical. Many ethical arguments against the Ministry of Health, and even the WHO, were voiced. These organisations were accused of taking advantage of their authoritative status and the trust the public places in them. In addition, many arguments regarding lack of transparency were expressed; some suggested that the mainstream media were concealing the truth from the public.

For the quantitative data collection, the Hypertext Preprocessor (PHP) script available from the Facebook site was used to collect each post's first 25 comments in the aforementioned Facebook group. A purposive subsampling procedure led to a final sample of 401 items, which were then subjected to a quantitative content analysis approach that involved coding the topics covered in each item, the socio-demographics of the writers, and their use of evidence.

Although, as detailed above, the qualitative analysis suggested that dialogue became more political than scientific overall, the quantitative analysis showed that the discussants did not abandon the scientific nature of the issue at hand. Of the frequent contributors to Parents Talk About Polio Vaccination, 22 were physicians who answered questions and addressed concerns rather than initiated discussions. They were responsible for 15% (n = 59) of the items. Nevertheless, only 3% of the items (13 items) contained an explicit reference to self-expertise (e.g., "I am a doctor"). Of the 401 items analysed, 50.1% (201 items) had scientific or medical topics as their primary content, even though empirical evidence was barely cited. There was a significant association between stance on polio vaccination and the use of evidence (x2 = 49.03, p < 0.005). Commentators who supported polio vaccination tended to employ more empirical evidence than those who opposed it or had a complex position.

Most of the items in the sample were pro-vaccination. This finding is in line with the high eventual compliance rates with the vaccination (59.2% among the Jewish population and 92.4% among the Arab population). In fact, studies on vaccine hesitancy suggest that the outcome of vaccine hesitancy is not necessarily non-compliance and can very often result in a decision to comply with vaccination.

In total, the results suggest that public engagement with science needs to be regarded in a more nuanced fashion, the researchers stress. The qualitative findings revealed that the discussion focused on fear of uncertain outcomes of vaccination, as well as on possible financial and political motivations for vaccination. This implies that expert sources are evaluated mostly as political agents, and points to the importance of considering not only the understanding of scientific aspects but also the emotional and social context of vaccine hesitancy. In other words, focusing on science comprehension or use of empirical evidence may not be adequate to study and address vaccine hesitancy. The researchers opine that it is necessary, then, to "regard the 'science' component in public engagement with science as a broad and versatile constituent, which the public may interpret and deploy in many ways."

In conclusion: "Social media has recently emerged as an effective and strategic communication tool to address vaccine hesitancy and may become more important in coming years....The main contribution of this study is in its illustration that science has much more malleable boundaries than is sometimes assumed."