Vaccination Mandates and Their Alternatives and Complements

"[P]sychological research on vaccine uptake and hesitancy recognises the need for a more nuanced approach to mandates and alternative and complementary interventions."

Vaccination mandates, which are regulations that penalise non-vaccination, are often suggested as a solution to low vaccine uptake. However, mandates are criticised because they aim to simply bypass rather than actually overcome the cognitive, emotional, and social components of vaccine hesitancy. This review contextualises the costs and benefits of implementing vaccination mandates on the basis of the evidence of their effectiveness, ethical considerations, and unintended psychological effects. It presents a toolbox of alternative interventions to promote vaccine uptake, with a primary focus on the psychological mechanisms that drive behaviour change.

To provide grounding for the argument to follow, the review describes several general health behaviour theories and context-specific frameworks of vaccination decision-making that have been used to explain and predict vaccine uptake or its antecedents.
 

• Health behaviour theories: For example, the theory of planned behaviour focuses primarily on individuals' motivation as a key determinant of behaviour. Other theories, such as the Health Action Process Approach, focus more strongly on the antecedents of health behaviours beyond the motivational phase of the decision-making process.
• Context-specific frameworks that explain vaccination behaviour can be categorised as macro (e.g., social ecological models of health promotion), meso (e.g., the World Health Organization behavioural and social drivers of vaccination framework, the 5As taxonomy, or the 5C model), and micro (e.g., the 11 attitudes framework) frameworks.

Next, the paper briefly reviews evidence around vaccination mandates. Despite varying degrees of restrictiveness, vaccination mandates are considered the most restrictive intervention relative to other interventions for increasing vaccine uptake. This high restrictiveness has legal and ethical consequences. A key psychological objection against mandates is that they might trigger unintended cognitive, emotional, and behavioural reactions because they limit choice. For instance, they might trigger reactance, which can cause behavioural responses to restore freedom. Established theories of social psychology, motivation, and personality, which are outlined in the paper, provide a theoretical basis for this objection.

In light of this evidence, the paper considers which interventions psychological science has to offer to decrease vaccine hesitancy and increase vaccine uptake. It reviews these cognitive and emotional mechanisms. For example, when making vaccination decisions, individuals can use mental shortcuts (heuristics) to make rapid judgements about risks. One emerging finding is the role of the narrative bias, which describes the persuasiveness of personal stories (for example, about a single negative vaccine experience. The individual's perception of risk is biased by the intensity of the emotions arising from the narrative and the credibility of the narrative's source.

Next, the paper discusses specific interventions that are informed by an understanding of these cognitive and emotional processes. These interventions differ in their level of restrictiveness, depending on whether they aim to:
 

• Provide information (e.g., through informational classes, workshops, leaflets, or training) to influence cognitive and affective perceptions of risk - These interventions primarily act on deliberative processes. That is, they are usually more effective when individuals make analytical and thoughtful vaccination decisions rather than automated, intuitive, or spontaneous decisions that might take place, for example, under stress or time pressure.
• Enable change (e.g., through vaccination decision aids) - These interventions are designed to support shared decision-making between patients and clinicians by presenting several options, which can facilitate participatory healthcare interactions and increase perceptions of autonomy in patients.
• Guide through persuasion (e.g., through framing interventions (such as appeals to fear or disgust) that primarily act on intuitive rather than analytical decision-making processes - These interventions can maintain and even foster autonomy and free choice if they are designed in line with principles for ethical persuasion that include, among other things, the principle of respect for the persuadee.
• Guide through environmental cues (e.g., through 'nudges', defaults in which vaccination is the presumed option, reminders/recall, or on-site vaccination) - These interventions are often designed to bypass deliberation and therefore are considered to be more restrictive than risk communication, message framing, or decision aids. However, these interventions predictably alter behaviour without using legal sanctions or economic incentives, thereby maintaining freedom of choice.

Such interventions, which help to overcome cognitive and emotional barriers to vaccination, are more likely to be effective if individuals are already in favour of vaccination or are already open to change. The process of initiating behaviour change becomes more difficult if individuals' hesitancy is rooted in underlying ideologies, worldviews, and identity needs that provide fertile ground for biased information processing, known as motivated reasoning. For example, some individuals are conflicted about getting vaccinated because they are also motivated to defend their existing moral, political, or religious values - values perceived as being threatened by vaccination. Interventions to overcome motivated reasoning aim to rebut misinformation and guide through persuasion, to specifically avoid triggering reactance and enable change, or to combine both interventions. One example includes dialogue-based interventions, particularly those that leverage people's trust in healthcare providers, such as motivational interviewing (MI) or the Empathetic Refutational Interview.

Furthermore, as outlined here, the social component of vaccination decision-making is one of the central factors influencing a person's willingness to get vaccinated. For example, individuals might be conflicted because they believe that getting vaccinated is not socially accepted or because they are unaware of the social benefits of vaccinations. The paper explores vaccinations as a social contract and reviews interventions that facilitate adherence to the social contract. For example, one possible strategy to promote vaccination as other-regarding behaviour is to educate the public about the concept and implications of community protection. This intervention is considered non-restrictive, as it relies on the provision of information. Emphasising social norms regarding the adherence to the social contract can also be utilised in interventions to increase vaccine uptake. Interventions that use this approach are considered more restrictive than only communicating collective benefits because they guide through persuasion.

Finally, the review examines use of financial incentives to vaccinate, which are often more accepted by the population than vaccination mandates. These alternatives are considered less restrictive than vaccination mandates but more restrictive than other alternative interventions, because individuals with low income might be unable to turn down high rewards, even if this means going against their beliefs and values.

Overall, these interventions vary in degree of restrictiveness but are ultimately designed to preserve freedom of choice. They can be implemented in addition or as an alternative to mandates to tackle the psychological roots of vaccine hesitancy. There is also evidence that at least some of the alternative and complementary interventions can result in behaviour change. Research on, among other things, motivational interviewing, scientific consensus messaging, reminder and recall systems, and direct payments provides evidence that these interventions can affect vaccine uptake. The proposed interventions are not mutually exclusive; combining interventions that harness multiple mechanisms is advisable.  

The review of the evidence in psychological science offers three key lessons:
 

1. Policymakers should consider the toolbox of effective interventions offered here as alternatives or complementary measures to tackle the psychological roots of vaccine hesitancy, rather than merely addressing its "symptoms" by using vaccine mandates.
2. Before any intervention is implemented, less restrictive measures should be considered, alongside their feasibility and impact.
3. Each country requires constant public support monitoring to select suitable interventions from the toolbox and to design the specific policy needed in each context.

The paper concludes by sharing some avenues for future research. For example, studies could focus on testing and comparing interventions and their combinations from the proposed toolbox in a targeted manner rather than applying a one-size-fits-all approach. Most randomised controlled trials that have tested the effectiveness of interventions on vaccine uptake have focused on the general public. Yet there are many nuances. Individuals who are hesitant owing to concerns about the safety of vaccination can benefit from interventions that specifically address those concerns (for example, MI) but are unlikely to be convinced by financial incentives. By contrast, unvaccinated individuals who have a high confidence in vaccination might not benefit from mass communication campaigns or individual conversations but might need structural changes that support the implementation of their strong intentions. Cognitive-emotional and motivation-focused models of belief formation and vaccination decision-making can inform the design of such investigations.