Discussion
Although evidence-based communication interventions to promote HeVD vaccination by horse owners were not identified, the BeSD framework enabled orientation and synthesis of the research on horse owner vaccine decision-making, suggesting that the BeSD framework could be adopted to understand HeVD vaccination uptake by horse owners.
The BeSD framework was originally developed to characterise the drivers of parental decisions to vaccinate children (and later COVID vaccine decisions among adults) (World Health Organization, 2022a), and this review demonstrates that there are similarities between the underlying drivers of vaccination decisions among horse owners and parents. Most lie within the BeSD Thinking and Feeling Domain in which non-vaccinating parents also perceive low disease risk, are concerned about vaccine side-effects, believe that vaccines are unsafe and ineffective, and share mistrust of health professionals (Brown et al., 2010; Chow, Danchin, Willaby, Pemberton, & Leask, 2017; Smith, Amlôt, Weinman, Yiend, & Rubin, 2017). Fitting under the BeSD Social Processes Domain, the social “othering” and dismissal by medical professionals that is experienced by some non-vaccinating parents (Wiley et al., 2021) is like the ostracism from veterinarians experienced by HeVD-vaccine skeptical horse owners (Manyweathers et al., 2020). Within the same domain, healthcare provider recommendations to parents are akin to those from veterinarian to horse owners (Crawford & Leask, 2022; Helps, Leask, Barclay, & Carter, 2019; Smith et al., 2017). Within the BeSD Practical Issues Domain, the cost of vaccination as an influence on horse owner vaccination decisions also influences parents vaccination decisions; for example, cost is a known barrier to Meningococcal B vaccination, which is not included in the National Immunisation Program schedule for all non-Indigenous Australian children (Taha et al., 2022; Wang, Clarke, Afzali, & Marshall, 2014).
The BeSD Motivation Domain is a point at which the populations might differ. It is not possible to quantify the probability of intention to vaccinate (motivation) in the current review; however, it is clear that there are groups of horse owners with little motivation to vaccinate their horses against HeVD, and overall, motivation must be lower than that of parents for childhood vaccines because there is currently >95% versus ~12% uptake for childhood vaccines and HeVD vaccine, respectively (M. Taylor et al., 2016; Wiley et al., 2021). Horse owners behave similarly to parents in that increased risk perception will result in increased vaccination motivation (Helps et al., 2019), but the complexity of HeV transmission necessitates that HeVD prevention extends beyond vaccine acceptance to include non-pharmaceutical approaches which do not necessarily align well with the current vaccine-focused BeSD framework. This complexity was acknowledged in the community juries study, in which participants identified the need for better communication and public education about the behaviours, ecological benefits, and zoonotic risk that bats pose (Degeling et al., 2018). Where the biggest barriers to HeVD vaccination lie – whether associated with the domains of ‘Thinking and Feeling’ and ‘Social Processes’ or the domain of ‘Practical Issues’ – needs further investigation beyond this preliminary appraisal.
This review highlighted both similarities and differences in the perceptions, feelings, motivations, social processes, and practical issues that horse owners and parents face in the context of HeVD and childhood vaccine decision-making, respectively. It provides insights about how horse owners engage with HeVD information and how the information influences their behaviour, and the circumstances in which horse owners might consider HeVD vaccination. This information, which is part of the why  behind the low uptake of HeVD risk mitigation behaviour by horse owners, now needs to be measured to know their relative importance (Manyweathers, Field, Longnecker, et al., 2017; Wiethoelter et al., 2017; WHO, 2022a) as well as assessment and integration of other influencing factors such as the use of alternative mitigation strategies and zoonotic transmission risk. Once adapted for the HeVD context, the BeSD framework could be used to systematically measure the drivers of HeVD vaccination to inform the development of communication or educational interventions (WHO, 2022a). Following implementation of such HeVD communication interventions, BeSD data collection tools could then be used to monitor and evaluate the interventions, and to guide interventions to reduce HeVD vaccine coverage gaps (WHO, 2022a), thus reducing the risk of HeVD to horses and people.