In this study we interviewed Australian horse owners who had elected not to vaccinate their animals (N=15) and equine veterinarians (N=10), all located in areas of previous Hendra virus cases. Our results revealed how expert knowledge was identified and valued and by whom, and how this contributed to the divisive discourses. Disqualification by institutional and industry experts of lay knowledge and experience also played a role in creating barriers to progressive and inclusive discussions around risk mitigation. Inadequate handling of uncertainty, including the opacity of the vaccine development and registration process, and the handling of vaccine injury reports contributed to the polarisation of communications around Hendra virus and the vaccine.

We assert that examination of how experts are trained must be undertaken. By including explicit training in inclusive and reflective risk communication practices, experts will be better prepared for their role as science communicators. This will contribute to the acknowledgement of legitimacy of diverse knowledge sources and the inevitability of uncertainty, which will enhance future communications around management of infectious diseases.