An assessment of risk compensation and spillover behavioural adaptions associated with the use of vaccines in animal disease management

Gareth Enticott,Damian Maye,Rhiannon Naylor,Lucy Brunton,Sara H Downs,Christl A Donnelly

doi:10.1016/j.vaccine.2019.11.037

Abstract

This paper analyses farmers’ behavioural responses to Government attempts to reduce the risk of disease transmission from badgers to cattle through badger vaccination. Evidence for two opposing behavioural adaptions is examined in response to the vaccination of badgers to reduce the risk of transmission to farmed cattle. Risk compensation theory suggests that interventions that reduce risk, such as vaccination, are counterbalanced by negative behavioural adaptions. By contrast, the spillover effect suggests that interventions can prompt further positive behaviours. The paper uses data from a longitudinal mixed methods study of farmers’ attitudes to badger vaccination to prevent the spread of bovine tuberculosis, their reports of biosecurity practices, and cattle movement data in 5 areas of England, one of which experienced badger vaccination. Analysis finds limited evidence of spillover behaviours following vaccination. Lack of spillover is attributed to farmers’ beliefs in the effectiveness of biosecurity and the lack of similarity between badger vaccination and vaccination for other animal diseases. Risk compensation behaviours are associated with farmers’ beliefs as to who should manage animal disease. Rather than farmers’ belief in vaccine effectiveness, it is more likely that farmers’ low sense of being able to do anything to prevent disease influences their apparent risk compensation behaviours. These findings address the gap in the literature relating to farmers' behavioural adaptions to vaccine use in the management of animal disease.

Highlights

Risk compensation theory suggests that initiatives to reduce risk are counterbalanced by greater risk taking [1,2]
This paper has investigated for the first time whether risk compensation and/or spillover behaviours are associated with the vaccination of wildlife to control the spread of animal disease
In focusing on the behavioural impacts amongst farmers of badger vaccination, this paper finds limited evidence of spillover behaviour whilst apparent risk compensation behaviour may be better explained as a reaction to low self-efficacy and a poor match between vaccination and farmers’ cultural understandings of disease management

Summary

Introduction

Risk compensation theory suggests that initiatives to reduce risk are counterbalanced by greater risk taking [1,2]. A lack of trust between the government and farmers [31], debate over the ownership of disease management, and increasing incidence of bTB may contribute to risk compensation behaviours by encouraging low self-efficacy and fatalistic attitudes amongst farmers [32,33]. Behavioural spillovers such as implementing additional biosecurity measures to limit contact between badgers and cattle may be connected to vaccination. Culling can create a perturbation effect in badger populations [39] that increases the risk of disease transmission prompting the need for additional biosecurity. Defra stated that observation of long-term research studies of badger populations meant that vaccination was ‘very unlikely’ to cause perturbation [28], this was subsequently confirmed by analysis which found no evidence of perturbation arising from badger vaccination [40]

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Conclusion