How to cite this article: Vet. Res. (2008) 39:60
DOI: 10.1051/vetres:2008037

Construction and testing of a novel host-range defective myxoma virus vaccine with the M063 gene inactivated that is non-permissive for replication in rabbit cells

Mathew M. Adams^{1, 2}, Barbara H. van Leeuwen¹, Grant McFadden³ and Peter J. Kerr<sup>4

1</sup>  School of Biochemistry and Molecular Biology, College of Science, The Australian National University, Canberra, ACT 0200, Australia
²  Current address: Johnson and Johnson Research Pty Ltd, Level 4, 1 Central Avenue, Eveleigh, NSW 1430, Australia
³  Department of Molecular Genetics and Microbiology, College of Medicine, University of Florida, 1600 SW Archer Rd, Academic Research Building, PO Box 100266, Gainesville 32610, Florida, USA
⁴  CSIRO Entomology, GPO Box 1700, Canberra, ACT 2601, Australia

Received 23 January 2008; accepted 4 September 2008; published online 9 September 2008

Abstract - Deletion of the M063 gene from myxoma virus produces a virus that is unable to replicate in rabbit cells in vitro or in live rabbits but can be propagated in non-rabbit cell lines. A targeted M063 deletion mutant was constructed in the attenuated Uriarra strain of myxoma virus and the ability of this virus to act as a safe, non-transmissible vaccine against myxomatosis was tested in outbred laboratory rabbits. Immunization with the M063 deletion vaccine provided good short-term protection against lethal challenge with virulent myxoma virus. Long-term protection was similar to reported results with heterologous live virus, with some rabbits protected but others succumbing to challenge. Replication-deficient poxvirus vaccines, like the Modified Vaccinia Virus Ankara (MVA) in man and the myxoma virus vaccine described here in rabbits, are very attractive from a safety perspective. Seasonal boosting would be predicted to provide long-term protection. Targeted host-range gene deletions could have potential for rapid development of poxvirus vaccines in general.

Key words: myxomatosis / vaccine / host-range / poxvirus / rabbits

Corresponding author: peter.kerr@csiro.au

© INRA, EDP Sciences 2008