Status: Completed

Start date: 1 July 2018

Completion date: 30 September 2022

Project code: P01-B-001

Species: European rabbits

Download project report (PDF, 3.42 MB)

Summary

European rabbits have become Australia’s most widespread and destructive environmental and agricultural vertebrate pest. One way Australia ‘battles the bunny’ is using viruses.
Using inoculation trials, the project team examined how RHDV2 (rabbit haemorrhagic disease virus strain 2) spreads, how fast, how it evolves, how it interacts with other viruses, and whether it would be an effective extra tool for biocontrol. The results, from most trapping sites and in most months, were consistent with other work indicating that RHDV2 is dominant in Australia.

Key achievements

Outputs

  • Multivalent RHDV2 vaccine in trials for use by commercial breeders and rabbit pet owners.
  • Over a dozen scientific publications and book chapters understanding immunology, and serology of RHDV2.

Outcomes

  • Greater understanding of RHDV2, its role in the landscape and interactions with other rabbit pathogens.
  • Progress towards RHDV2 vaccine.

Impact

  • Contribution to increased effectiveness of ongoing rabbit biocontrol in Australia through improved understanding of endemic RHDV2.
  • Potential contribution to maintaining lower rabbit impact costs through future registration of an RHDV2 biocide..
  • Increased efficiency and effectiveness of resource allocation for RD&E associated with rabbit biocontrol.
  • Contribution to improved environmental outcomes in the future through improved management of wild rabbits.
  • Contribution to a maintained social licence to operate for invasive species managers using RHDV or other biocontrol agents for rabbits by developing and registering effective vaccines for domestic rabbits.
  • Increased scientific knowledge and research capacity associated with biological control of rabbits.

Project team

Dr Pat Taggart

Project Lead | NSW DPI

Dr Tarnya Cox

NSW DPI

Dr Peter Fleming

NSW DPI

Quentin Hart

NSW DPI

Dr Andrew Read

NSW DPI

Dr Peter Kirkland

NSW DPI

Trudy Sharp

NSW DPI

Dr Tanja Strive

CSIRO

Dr Robyn Hall

CSIRO

Dr Peter Caley

CSIRO

Ridma Jayasinghe

PIRSA

Dr Bhumi Savaliya

PIRSA

Dr Brad Page

PIRSA

Sammi Chong

CSIRO

Dr Sahra McFetridge

PIRSA

Dr Kandarp Patel

PIRSA

Project partners

The project received funding from the Australian Government Department of Agriculture, Fisheries and Forestry (DAFF).

Project updates

February 2021

Experiments have been undertaken to contribute data to understanding the interactions between the different genotypes of RHDV. The experiments involved studying the “protection” afforded by both natural infection and maternal antibodies, as well as studies involving immunity induced by vaccination. These data confirm that; a) the challenge viruses cause extremely high mortality rates (approaching 100%) b) that RHDV2 has a very variable capacity to overcome immunity c) that the K5 strain of RHDV1 has the capacity to overcome immunity to RHDV2 strains in a moderate proportion of rabbits.

August 2020

RHDV2 virulence trials in both adult and young domestic rabbits are complete, the results are currently being prepared for publication. Trials have commenced into how maternal antibodies protect young rabbits against RHDV2 infection. A humaneness assessment of RHDV2 infections was completed using an established welfare matrix scoring process. The updated welfare assessment will be made available through PestSmart.
Good progress is being made towards a multivalent vaccine and a research permit for use of a prototype monovalent RHDV2 vaccine has been submitted to the AVPMA and is awaiting approval.

February 2020

A component of the RHDV2 registration package has been prepared for submission to the APVMA.
The virulence of RHDV2 has been assessed in both adult and young laboratory rabbits. Studies investigating the effects of maternal antibodies on RHDV2 infection have commenced in laboratory rabbits.

August 2019

Assessment of the virulence and welfare impacts of RHDV2 in both adult and young rabbits is almost complete. 100% case fatality rate has been observed in laboratory rabbits, with a short illness duration.
Another project aspect is investigating the effect of maternal immunity on the ability of young rabbits to get infected with RHDV2 – a critical piece of information that will inform the timing of any future applications of RHDV2 as an additional biocide.

February 2019

This project is supporting research into the potential registration of RHDV2 as a biological agent for control of wild rabbits. It is unclear how the survival of rabbits is influenced by previous infections by one or more strains of RHDV. Understanding these interactions will inform which RHDV strains may be best suited for release at different times of the year and in different parts of Australia. A component of this work has commenced that experimentally assesses the ability of different virus strains to overcome pre-existing immunity to other strains in wild rabbits.

Another component of this project, the development of a prototype monovalent vaccine for RHDV2 is progressing well.

Scientific publications & reports

Cox T, Ramsey D, Sawyers E, Campbell S, Matthews J and Elsworth P (2019) The impact of RHDV-K5 on rabbit populations in Australia: an evaluation of citizen science surveys to monitor rabbit abundance. Scientific Reports 9(15229). https://www.nature.com/articles/s41598-019-51847-w

Elfekih S, Metcalfe S, Walsh TK, Cox TE and Strive T (2022) ‘Genomic insights into a population of introduced European rabbits Oryctolagus cuniculus in Australia and the development of genetic resistance to rabbit hemorrhagic disease virus’, Transbound Emerg Dis, 69:895–902, https://doi.org/10.1111/tbed.14030

Hall R, Huang N, Roberts J and Strive T (2019) ‘Carrion flies as sentinels for monitoring lagovirus activity in Australia’, Transboundary and Emerging Diseases, 66(5):2025–2032. https://doi.org/10.1111/tbed.13250

Hall RN, King T, O’Connor T, Read AJ, Arrow J, Trought K, Duckworth J, Piper M and Strive T (2021) Age and infectious dose significantly affect disease progression after RHDV2 infection in naive domestic rabbits. Viruses 13(6), 1184. https://doi.org/10.3390/v13061184

Hall RN, King T, O’Connor TW, Read AJ, Vrankovic S, Piper M and Strive T (2021) Passive immunity against RHDV2 induces protection against disease but not infection Vaccines 9(10), 1197. https://doi.org/10.3390/vaccines9101197

Jenckel M, Hall RN and Strive T (2022) Pathogen profiling of Australian rabbits by metatranscriptomic sequencing. Transboundary and Emerging Diseases69(5), pp.e2629-e2640. https://doi.org/10.1111/tbed.14609

Kerr P, Hall RN and Strive T (2021) Viruses for landscape-scale therapy: Biological control of rabbits in Australia. In ‘Viruses as Therapeutics: Methods in Molecular Biology’ (editor Lucas AR). Humana, New York, NY. https://doi.org/10.1007/978-1-0716-1012-1\_1.

Kerr P and Strive T (2020) Biological control of vertebrates: Myxoma virous and rabbit hemorrhagic disease virus as biological control for rabbits, In ‘Managing Biological and Ecological Systems’ (Fath BD and Jorgensen SE eds). CRC Press. https://doi.org/10.1201/9780429346170

Mahar JE, Jenckel M, Huang N, Smertina E, Holmes EC, Stive T and Hall R (2021) Frequent intergenotypic recombination between the two non-structural genes is a major driver of epidemiological fitness in calicivirus (submitted), https://www.biorxiv.org/content/biorxiv/early/2021/02/18/2021.02.17.431744.full.pdf

O’Connor TW, Read AJ, Hall RN, Strive S and Kirkland PD (2022) Immunological cross-protection between different rabbit haemorrhagic disease viruses: implications for rabbit biocontrol and vaccine development Vaccines 10(5), 666. https://doi.org/10.3390/vaccines10050666

Pacioni C, Hall RN, Strive T, Ramsey DSL, Gilland M and Vaughan TG (2022) ‘Comparative epidemiology of rabbit haemorrhagic disease virus strains from viral sequence data’. Viruses, 15(1): 21 https://doi.org/10.3390/v15010021

Pacioni C, Vaughan TG, Strive T, Campbell S and Ramsey DL (2021) Field validation of phylodynamic analytical methods for inference on epidemiological processes in wildlife Transboundary and Emerging Diseases 69(3), 1020-1029, https://doi.org/10.1111/tbed.14058

Patel KK, Strive T, Hall RN, Mutze G, Page B, Korcz M, Booth-Remmers M, Smith IL, Huang N, Kovaliski J, Jayasinghe Ellakkala Appuhamilage RMJ and Taggart PL (2002) Cross-protection, infection and case fatality rates in wild European rabbits experimentally challenged with different rabbit haemorrhagic disease viruses Transboundary and Emerging Diseases, https://doi.org/10.1111/tbed.14530

Ramsey D, Cox T, Strive T, Forsyth D, Stuart I, Hall R, Elsworth P and Campbell S (2019) Emerging RHDV2 suppresses the impact of endemic and novel strains of RHDV on wild rabbit populations Journal of Applied Ecology 57(3), 630-641. https://doi.org/10.1111/1365-2664.13548

Ramsey DS, Patel KK, Campbell S, Hall RN, Taggart PL, Strive T (2023) Sustained Impact of RHDV2 on Wild Rabbit Populations across Australia Eight Years after Its Initial Detection Viruses 15, 1159. https://doi.org/10.3390/v15051159

Strive T, Piper M, Huang N, Mourant R, Kovaliski J, Capucci L, Cox T and Smith I (2020) Retrospective serological analysis reveals presence of the emerging lagovirus RHDV2 in Australia in wild rabbits at least five months prior to its first detection Transboundary and Emerging Diseases 67(2), 822-833. https://doi.org/10.1111/tbed.13403

Strive T and Cox T (2019) ‘Lethal biological control of rabbits – the most powerful tools for landscape-scale mitigation of rabbit impacts in Australia’, Australian Zoologist, 40(1):118–128. https://doi.org/10.7882/AZ.2019.016

Taggart PL, Cooke B, Peacock DE et al (2024) Do land managers apply best-practice integrated pest management: a case study of the European rabbit. J Pest Sci . https://doi.org/10.1007/s10340-023-01720-7

Taggart PL, Hall RN, Cox TE, Kovaliski J, McLeod SR and Strive T (2022) Changes in virus transmission dynamics following the emergence of RHDV2 shed light on its competitive advantage over previously circulating variants Transboundary and Emerging Diseases, 69, 1118-1130, https://doi.org/10.1111/tbed.14071

Taggart PL, O’Connor TW, Cooke B, Read AJ, Kirkland PD, Sawyers E, West P and Patel K (2022) Good intentions with adverse outcomes when conservation and pest management guidelines are ignored: A case study in rabbit biocontrol Conservation Science and Practice 4(4), 12639. https://doi.org/10.1111/csp2.12639