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

Abstract

BackgroundHendra 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.MethodsThis 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.ResultsSelf-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.ConclusionWhile 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.Electronic supplementary materialThe online version of this article (doi:10.1186/s12917-017-1006-7) contains supplementary material, which is available to authorized users.

Investigation of the effect of Equivac® HeV Hendra virus vaccination on Thoroughbred racing performance

“…The most frequently given reasons for non-adoption of HeV vaccination by some horse owners and horse associations have been concerns about the potential for adverse reactions and effects on performance caused by vaccination. [18][19][20] The findings of this research provide evidence to diminish concerns regarding the HeV vaccine's safety and specifically its potential effect on horse performance. Equine veterinarians may use these results to provide evidence-based recommendations regarding preventive horse healthcare and allow horse owners to make informed decisions regarding HeV vaccination.…”

“…Equine HeV vaccination has proved controversial for a variety of reasons, including the way the vaccine was brought to market, workplace health and safety considerations for veterinarians, delays in HeV exclusion testing and implications for equine export and insurance. [18][19][20]30 Unlike most other vaccines in Australia, the HeV vaccine was initially launched under a Minor Use Permit, which was Figure 1. Fitted line plot of two slopes for mean modelled Timeform rating in the 3 months before versus after initial Hendra virus vaccination with observed Timeform rating data for 4197 race starts by 755 horses overlaid.…”

“…9 Despite the sound reasoning behind the vaccine's unconventional release, early views held by some horse owners were that the vaccine was unsafe and insufficiently tested. 18,19 The initial requirement for boosters to be administered at 6-monthly intervals, and the delay in APVMA approval for use in pregnant mares until 2016, were also likely reasons for some to conclude that there may have been early safety and efficacy concerns with the vaccine and that veterinarians' recommendations to vaccinate were largely motivated by financial gain. 18,19,31 All facets of the safety, efficacy and adverse reaction reporting process were reviewed by the Queensland Parliamentary Inquiry in 2016, with the vaccine being verified to be safe and effective.…”

“…17 Concerns regarding adverse reactions and reduced performance are frequently given as reasons for non-adoption of vaccination by some horse owners. 18,19 As part of a Queensland Parliamentary Inquiry into the HeV vaccine and its use by veterinarians in Queensland, the APVMA, the vaccine manufacturer Zoetis and the Australian Veterinary Association argued that the levels of adverse reactions to the HeV vaccine are low and well within the normal acceptable range for other types of vaccines. 20 Other individuals and performance horse association representatives lodged their concerns regarding vaccine safety at the Inquiry.…”

News

“…Although an effective vaccine for Hendra virus in horses is now available, 12 uptake of the vaccine has been well below expected levels 13 and recent analysis suggests as many as 400,000 horses remain unvaccinated and at risk. 14 The Hendra virus vaccine is the most effective way to prevent spillover to individual horses; 15 it is unknown to what extent current vaccination rates will affect the overall incidence of spillover events if there is a repeat of 2011 conditions.…”