“Why won’t they just vaccinate?” Horse owner risk perception and uptake of the Hendra virus vaccine

J. Manyweathers, H. Field, N. Longnecker, K. Agho, C. Smith, M. Taylor

Hendra virus is a paramyxovirus that causes periodic serious disease and fatalities in horses and humans in Australia first identified in 1994. Pteropid bats (commonly known as flying-foxes) are the natural host of the virus, and the putative route of infection in horses is by ingestion or inhalation of material contaminated by flying-fox urine or other bodily fluids. Humans become infected after close contact with infected horses. Horse owners in Australia are encouraged to vaccinate their horses against Hendra virus to reduce the risk of Hendra virus infection, and to prevent potential transmission to humans. After the vaccine was released in 2012, uptake by horse owners was slow, with some estimated 11-17% of horses in Australia vaccinated. This study was commissioned to examine barriers to vaccine uptake and potential drivers to future adoption of vaccination by horse owners. This study examined qualitative comments from respondents to an on-line survey, reporting reasons for not vaccinating their horses. The study also investigated scenarios in which respondents felt they might consider vaccinating their horses. Self-reported barriers to uptake of the Hendra virus vaccine by horse owners (N = 150) included concerns about vaccine safety, cost, and effectiveness. Reduction in vaccination costs and perception of immediacy of Hendra virus risk were reported as being likely to change future behaviour. However, the data also indicated that horse owners generally would not reconsider vaccinating their horses if advised by their veterinarian. While changes to vaccine costs and the availability data supporting vaccine safety and efficacy may encourage more horse owners to vaccinate, this study highlights the importance of protecting the relationship between veterinarians and horse owners within the risk management strategies around Hendra virus. Interactions and trust between veterinarians and animal owners has important implications for management of and communication around Hendra virus and other zoonotic disease outbreaks.