A chimeric vaccine protects farmed saltwater crocodiles from West Nile virus-induced skin lesions

Gervais Habarugira; Jessica J Harrison; Jasmin Moran; Willy W Suen; Agathe M G Colmant; Jody Hobson-Peters; Sally R Isberg; Helle Bielefeldt-Ohmann; Roy A Hall

doi:10.1038/s41541-023-00688-w

A chimeric vaccine protects farmed saltwater crocodiles from West Nile virus-induced skin lesions

NPJ Vaccines. 2023 Jun 27;8(1):93. doi: 10.1038/s41541-023-00688-w.

Authors

Gervais Habarugira^{1

2}, Jessica J Harrison², Jasmin Moran³, Willy W Suen^{2

4}, Agathe M G Colmant^{2

5

6}, Jody Hobson-Peters^{2

5}, Sally R Isberg³, Helle Bielefeldt-Ohmann^{7

8}, Roy A Hall^{9

10}

Affiliations

¹ School of Veterinary Science, The University of Queensland, Gatton, QLD, Australia.
² School of Chemistry and Molecular Biosciences, The University of Queensland, St Lucia, Australia.
³ Centre for Crocodile Research, Noonamah, NT, Australia.
⁴ Australian Centre for Disease Preparedness, The Commonwealth Scientific and Industrial Research Organisation, Geelong, VIC, 3219, Australia.
⁵ Australian Infectious Diseases Research Centre, The University of Queensland, St Lucia, QLD, Australia.
⁶ Unité des Virus Émergents (UVE) Aix-Marseille Univ-IRD 190-Inserm 1207, Marseille, France.
⁷ School of Chemistry and Molecular Biosciences, The University of Queensland, St Lucia, Australia. h.bielefeldtohmann1@uq.edu.au.
⁸ Australian Infectious Diseases Research Centre, The University of Queensland, St Lucia, QLD, Australia. h.bielefeldtohmann1@uq.edu.au.
⁹ School of Chemistry and Molecular Biosciences, The University of Queensland, St Lucia, Australia. roy.hall@uq.edu.au.
¹⁰ Australian Infectious Diseases Research Centre, The University of Queensland, St Lucia, QLD, Australia. roy.hall@uq.edu.au.

Abstract

West Nile virus (WNV) causes skin lesions in farmed crocodiles leading to the depreciation of the value of their hides and significant economic losses. However, there is no commercially available vaccine designed for use in crocodilians against WNV. We tested chimeric virus vaccines composed of the non-structural genes of the insect-specific flavivirus Binjari virus (BinJV) and genes encoding the structural proteins of WNV. The BinJV/WNV chimera, is antigenically similar to wild-type WNV but replication-defective in vertebrates. Intramuscular injection of two doses of BinJV/WNV in hatchling saltwater crocodiles (Crocodylus porosus) elicited a robust neutralising antibody response and conferred protection against viremia and skin lesions after challenge with WNV. In contrast, mock-vaccinated crocodiles became viraemic and 22.2% exhibited WNV-induced lesions. This suggests that the BinJV/WNV chimera is a safe and efficacious vaccine for preventing WNV-induced skin lesions in farmed crocodilians.