Towards Intervention Development to Increase the Uptake of COVID-19 Vaccination among Those at High Risk: Outlining Evidence-based and Theoretically Informed Future Intervention Content

"[V]accination behaviours could 'piggy-back' onto the wider behavioural system of COVID-related change."

The success of vaccination as a strategy for controlling the COVID-19 pandemic relies upon public acceptance of the vaccine. Vaccine hesitancy was evident during the last worldwide pandemic (H1N1 "swine flu" in 2009), with most countries reporting that less than half of the intended population received the vaccine. However, perceptions of risk related to COVID-19 are likely to be higher than for the 2009 pandemic, which may increase uptake of vaccination. The current study aimed to identify and understand the barriers and facilitators to receiving a future COVID-19 vaccine and, using the Behaviour Change Wheel (BCW) as a framework, to provide recommendations for the design of interventions aimed at maximising uptake of the vaccine among the public.

The BCW is based on the synthesis of 19 existing behaviour change frameworks and has the Capability Opportunity Motivation-Behaviour (COM-B) model at the centre (Michie, Stralen, & West, 2011). The COM-B model describes behaviour as the interaction between an individual's capability, opportunity, and motivation to engage in the behaviour with 6 components that drive behaviour (physical capability, psychological capability, physical opportunity, social opportunity, reflective motivation, and automatic motivation). These COM-B components are linked to intervention functions (education, persuasion, incentivisation, coercion, training, enablement, modelling, environmental restructuring, restrictions) through which an intervention can change behaviour, and 7 broad policy categories (guidelines, environmental/social planning, communication/ marketing, legislation, service provision, regulation, fiscal measures). Intervention functions are then linked to behaviour change techniques (BCTs), which are the active ingredients of an intervention, with BCT groupings of goals and planning, feedback and monitoring, social support, shaping knowledge, natural consequences, comparison of behaviour, associations, repetition and substitution, comparison of outcomes, reward and threat, regulation, antecedents, identity, scheduled consequences, self-belief, and covert learning.

During the United Kingdom (UK)'s early April 2020 "lockdown" period, 527 high-risk participants (311 older adults, mean age = 70.4 years; 216 chronic respiratory participants, mean age = 43.8 years) completed an online questionnaire assessing willingness to receive a COVID-19 vaccine, perceptions of COVID-19, and intention to receive influenza and pneumococcal vaccinations. A free text response (n = 502) examined barriers and facilitators to uptake. The BCW informed the analysis of these responses, which were coded to the Theoretical Domains Framework (TDF). BCTs were identified.

The survey found that 58% of the sample (n = 307) would definitely want to receive a vaccine for COVID-19 once it becomes available, and 27% (n = 143) probably would want to receive it. Pearson's correlation analysis showed that willingness to receive a COVID-19 vaccination was positively associated with the belief that the COVID-19 outbreak is going to continue for a long time, and negatively associated with the belief that the media has exaggerated the risks of catching COVID-19.

The data also suggest that COVID-19 may have a substantial and positive impact on vaccination behaviour in general, with 38% saying it will make them more likely to get the annual flu vaccine, and 51% saying they will now be more likely to receive the pneumococcal vaccine. These figures suggest positive unintended consequences of COVID-19 on vaccine hesitancy in general.

Content analysis of responses to the free text question "What are the factors that would influence this decision?" [receiving a vaccine for coronavirus] found that the majority of barriers and facilitators were mapped onto the "beliefs about consequences" TDF domain, with themes relating to personal health, health consequences to others, concerns of vaccine safety, and severity of COVID-19. The key barrier to vaccination was concern about vaccine safety, with participants worrying that the vaccine is being rushed into development.

Table 3 in the paper consolidates the key thematic findings, the relevant intervention functions, and appropriate BCTs. The right-hand column operationalises this suggested intervention content into potential intervention ideas that could form the basis of further focused intervention development work. Overall, the suggestions focus on ways of encouraging a decisional balance amongst those with some hesitancy to enhance vaccination uptake. This could be achieved through intervention materials fostering the appraisal of an array of consequences of vaccination; for example: "Intervention materials must ensure people consider the consequences of their individual vaccination behaviour for themselves, but critically, also for others; this could be linked to ideas of herd immunity and framed about protecting family and friends."

More specifically, analysis of the results through the lens of the BCW leads to the recommendation that the functions of education and persuasion are likely to be the most useful in the COVID-19 vaccine context. Education can improve knowledge of susceptibility and severity of COVID-19 and the effectiveness of vaccination, while persuasion can be used to change beliefs and encourage action towards vaccination. Because vaccination is likely to be needed at a population level, the mode of delivery for an intervention could be a combination of mass media (e.g., TV and radio, print media), social media, and close work with broadcasters and journalists to manage consistent messaging and challenge misinformation. The researchers surmise that a coherent media presence would enable the communication of strong descriptive and injunctive social norms concerning COVID-19 vaccination.

Further intervention development work could examine how interventions to enhance COVID-19 vaccine uptake could potentially build upon the public's prior investment in COVID-related behaviour change. This might include framing the intervention as associated with compliance with the lockdown and draw explicitly upon existing intervention messaging - for example "We're in this together" - and the protective discourse implied by concepts like "shielding". That is, intervention content could connect COVID-19-related behaviours, such as hand hygiene, social distancing, and volunteering, with vaccination compliance.

In conclusion, this study suggests that the content of mass media interventions to improve vaccine uptake should focus on the BCTs of information about health, emotional, social, and environmental consequences, as well as salience of consequences. "These techniques should be pitched in relation to both self and, most importantly, to others."