Vaccines and the Social Amplification of Risk

"...practical implications for guiding efforts to alleviate vaccine hesitancy and to mitigate harms from intentional and unintentional vaccine scares."

Vaccines provide fertile ground for questions, anxieties, concerns, and rumours, which appear in globalised hyperconnected communication landscapes and in the context of complex human (social, economic, and political) systems that exhibit evolving concerns about authority. This paper looks at the drivers, impacts, and implications of this landscape for vaccine initiatives in several recent historical examples and in the more recent efforts with COVID-19 vaccination. These experiences provide a window for viewing new forms of social amplification of risk (SAR). Findings and insights were drawn from the Vaccine Confidence Project (VCP)'s decade-long monitoring of media and social media and its related research efforts.

The paper opens by outlining the social amplification of risk framework (SARF), which was developed in the late 1980s in response to empirical observations in many settings that reported: (i) there were substantial differences between expert and lay perceptions of the nature and/or seriousness of a risk, (ii) such differences can have substantial impacts on behaviours that can amplify or mitigate the risk, and (iii) the perceptions and consequent behaviours may have spillover effects on other risks as well. As applied to the state of vaccine hesitancy, SARF explains that public perceptions vary widely, with much divergence from mainstream expert perceptions, and there has been significant resistance to vaccine uptake - the result of which has been higher risks of infection, as well as economic and social risks.

Practical implications for risks and for risk management were a primary concern in the creation of SARF. The framework identifies three stages for analysis:

1. A risk-related event or other news item relating to a risk is communicated and transformed through communication channels; the communication is further transformed as it is interpreted by an individual or organisation. Interpretation may alter individual or organisational perceptions.
2. The individual's or organisation's altered perceptions of risk influence their behaviour.
3. Individual or organisational behaviour will affect risk experiences; there may be direct impacts on the risk associated with the initiating event, as well as secondary and tertiary impacts on other risks.

The framework also anticipates feedback: thus, behavioural responses may influence further communications as communicators react to their audience and attempt to encourage or discourage particular behaviours.

As noted here: "Some care should be taken in applying the framework's analogy of an amplifier. In an acoustic system, an amplifier processes a signal: it may make it louder (amplification); it may make it softer (attenuation); or it may change the mixture of frequencies (distortion) including the possibility of adding new sounds. If we consider the initial event or news item as a signal, it will be potentially subject to each of these kinds of transformation as it passes through communication channels. But this only characterizes a portion of the relevant processes. An interpretation which leads to altered perceptions by an individual or organization of that transformed signal can also be considered an amplification process: so we may speak of the amplification, attenuation, or distortion of risk perceptions. Or we can consider the impacts of individual or organizational behavior: so, for instance, attenuated risk perceptions may lead to careless behavior that amplifies the risk."

The paper goes on to use the SARF in describing several historical examples of vaccine scares and hesitancy - e.g., the now-debunked claim by Andrew Wakefield in 1998 that the measles, mumps, and rubella (MMR) vaccine could be linked to autism in children - with data and interpretation largely derived from the work of the VCP. As Figure 1 in the paper illustrates, the initial claim in the Wakefield case served as a potent triggering event, and a number of reasons contributed to its powerful impacts on perceptions and behaviour. However, one of the biggest amplifiers of the "vaccines cause autism" meme was that Wakefield's paper came out the same year Google launched, followed in the coming years by the emergence of multiple social media platforms. The amplification enabled by these social media platforms went beyond what Wakefield could have imagined, allowing his meme, among others, to travel algorithmically through social networks of concerned parents seeking an answer to explain their child's autism or other vaccine-related concerns. These groups and channels kept the Wakefield claims alive long after their debunking and retraction. The loss of confidence in vaccines led (stage 3 of the SARF) to rising measles rates; concerns about vaccines spread from MMR to other vaccines and to a loss of confidence in medical authorities.

Other vaccine experiences exhibiting SAR outlined here include those with the human papillomavirus virus (HPV) vaccine, the Ebola vaccine, and the dengue vaccine. Unlike the HPV and Ebola experiences, in which government agencies and local politicians reacted to public concerns, in the case of Dengvaxia in the Philippines, a national leader used vaccine concerns in pursuit of a particular political agenda. Several further such examples appeared during the COVID-19 pandemic. As the paper details in section 5, the risk perceptions of COVID-19 disease and its vaccines had a striking divergence within and between experts and lay opinions, leading to contrasting behavioural and policy responses, ripple effects, and subsequent psychological and socioeconomical impacts at individual and societal levels. For example, uncertainty, a lack of complete information, and the "infodemic" around the disease and vaccines have presented an environment in which myths, misinformation, fake news, and rumours can fester and multiply. Some of the public figures, health officials, scientists, or researchers who disagree with scientific evidence about COVID-19 disease and the vaccines have also contributed to the creation and dissemination of misinformation and false claims, and they have attracted a widespread following. "What is often overlooked in the focus on misinformation and rumors, and the role of technology platforms in their spread, is the new opportunities for those sharing common beliefs and perceptions to self-organize online and recruit others to join their echo chambers."

As COVID-19 vaccine hesitancy has laid bare, SARF may need some adjustments, which section 6 of the paper explores - though a comprehensive update of SARF is not presented here. The challenges in coping with risks in complex systems were only partially addressed in the formulation of the SARF. The most prominent missing aspect is the transformed nature of communication through social media: its speed, its global reach, its interactive character, and its internal, algorithm-driven dynamics. The authors suggest that more attention is also needed (i) to tendencies toward increased politicisation and polarisation - both in communication channels and as a component of perceptions and (ii) to the upstream context in which communications take place and perceptions are formed (not just the interpretation and consequences of an event, as per the original SARF). "Just as significant will be the degree of trust in health authorities and other relevant institutions. Proactive gathering of information on these conditions and, when appropriate, proactive engagement with vulnerable communities are critical capabilities for an effective response."

The researchers illustrate the use of an augmented SARF by considering reactions to vaccine mandates. They continue to consider three stages for analysis (as in the original SARF), but they also explicitly identify a need for analysis of the context in which events, communications, and perceptual and behavioural changes occur. In the three stages, they give prominence to social media and the networks created within them. Because vaccine mandates can evoke considerations of political authority and personal liberty, political polarisation also feature in the analyses. This example is illustrated in Figure 3 of the paper.

Reflecting on the examples presented, both recent and old, and from the associated analysis, the researchers suggest that, as vaccine hesitancy has increased, the study of vaccine hesitancy is entering a new and more mature stage. Thus, the SARF must be revisited to be responsive to new conditions. Two aspects that call for deeper study are: (i) the complex characteristics and dynamics of the digital landscape through which much communication now occurs and (ii) the characteristics of the complex social systems that form the context in which information and misinformation about vaccines influence vulnerability to hesitancy or rejection of these and other medical interventions. Effort is needed to bring in more risk assessment and anticipatory measures in place of reactive responses devoted to debunking misinformation.

In supporting a robust approach to alleviate harmful hesitancy, the SARF's updated configuration should help:

• Identify and characterise deep pockets of harmful misinformation or efforts to undermine public trust, with a view toward developing effective interventions to build confidence in science.
• Develop better approaches and messages that can be deployed more quickly in response to potentially harmful messaging.
• Identify interventions that could enhance capabilities of communicative and interpretive processes to create resilience against the amplification of harmful messaging and influencing.
• Develop better diagnostic capabilities for identifying locations, population groups, and situations that are vulnerable to harm, with the goal of finding approaches to reduce such vulnerability.

In conclusion: "The digital revolution has profoundly altered communication and the development of new forms of social networks and their influence; the framework must take better account of these new dimensions and their role in the amplification of risk. The dramatic change in the landscape has brought into prominence the systemic nature of the realms in which social amplification occurs. It is not sufficient to consider how messages and perceptions can be amplified, suppressed, or distorted in isolation....[A] critical aspect will be achieving an appropriate balance between proactive and reactive efforts."