Virus-vectored immunocontraception for control of wild rabbits: identification of target antigens and construction of recombinant viruses

The need to control animal populations arises in many situations in the world from a variety of motives. Present control strategies are almost universally based on lethal procedures. Increasingly, there is dissatisfaction with such approaches from many different perspectives. In response to these concerns, the concept of controlling populations of pest species through control of their fertility has been mooted. Successful examples of this approach exist in cases of small, discrete pest populations but application of this to a widely distributed species over a broad geographical area has not yet been achieved. In this article, we report on a new approach to fertility control, virus-vectored immunocontraception, and discuss its applicability to control of wild rabbit populations. Particular emphasis is placed on the strategy for selection of a target molecule capable of inducing an immunocontraceptive response and on how the gene encoding such a molecule might be engineered into the myxoma virus for distribution into the population. The fact that the procedures for antigen identification and the viral engineering methods used are, to varying extents, generic means that the broad principles of this approach are applicable in other species.

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Progress towards using recombinant myxoma virus as a vector for fertility control in rabbits

Reproduction Fertility and Development ◽

10.1071/r96067 ◽

1997 ◽

Vol 9 (1) ◽

pp. 77 ◽

Cited By ~ 22

Author(s):

A. J. Robinson ◽

R. Jackson ◽

P. Kerr ◽

J. Merchant ◽

I. Parer ◽

...

Keyword(s):

Recombinant Virus ◽

Fertility Control ◽

Myxoma Virus ◽

Wild Rabbit ◽

Recombinant Viruses ◽

History Of ◽

Insertion Sites ◽

Influenza Virus Haemagglutinin ◽

Double Recombinant ◽

Virus Haemagglutinin

The history of myxoma virus, its use in Australia as a mortality agent and the development of the virus as a vector for controlling fertility in wild rabbit populations in Australia is reviewed. Myxoma virus recombinants have been constructed to express model antigens. Four potential insertion sites in the genome have been identified and two have been used to construct single and double recombinant viruses expressing Escherichia colienzymes β-galactosidase and β-glucuronidase. Another recombinant expressing an influenza virus haemagglutinin gene (A/PR8/34) induced high and sustained antibody responses following intradermal inoculation in rabbits. To demonstrate the potential of introducing a recombinant virus into wild rabbit populations, a virus containing a natural deletion was released at four field locations. Preliminary analysis of the data has shown that the introduced virus spread well on 3 of the 4 locations. The steps being taken to address the ethical and safety implications of the introduction of a recombinant virus into the field are discussed.

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Selection of antigens for use in a virus-vectored immunocontraceptive vaccine: PH-20 as a case study

Reproduction Fertility and Development ◽

10.1071/r96074 ◽

1997 ◽

Vol 9 (1) ◽

pp. 117 ◽

Cited By ~ 16

Author(s):

Michael K. Holland ◽

Jason Andrews ◽

Hannah Clarke ◽

Clayton Walton ◽

Lyn A. Hinds

Keyword(s):

Oryctolagus Cuniculus ◽

Genetically Engineered ◽

Myxoma Virus ◽

Wild Rabbit ◽

Pest Species ◽

Genes Encoding ◽

Overall Efficiency ◽

Selection Of ◽

Sperm Antigen

The European wild rabbit (Oryctolagus cuniculus) has become the major agricultural and environmental pest species in Australia. Current methods of rabbit control are lethal procedures which are increasingly questioned for their overall efficiency, applicability, specificity, cost and humaneness. New initiatives are required. One such initiative is virus-vectored immunocontraception. In this approach, the lagomorph-specific myxoma virus will be genetically engineered to include genes encoding components of rabbit gametes which can induce an immune response that causes infertility. Central to such a strategy is the ability to identify antigens capable of inducing an immunocontraceptive response. A strategy for identifying such antigens has been described previously. A case study of one sperm antigen, PH-20, is reported here. The issues involved in developing this antigen to the stage where it could be considered as a candidate for insertion into a recombinant myxoma virus with the ultimate goal of testing for immunocontraceptive efficacy are discussed. Techniques for inserting genes into myxoma virus have been described previously. The knowledge gained from research with this particular antigen are broadly applicable to other antigens used for both immunocontraceptive vaccines in general and, specifically, for virus-vectored immunocontraception.

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Disease and fertility control in wildlife and feral animal populations: options for vaccine delivery using vectors

Reproduction Fertility and Development ◽

10.1071/rd9940393 ◽

1994 ◽

Vol 6 (3) ◽

pp. 393 ◽

Cited By ~ 9

Author(s):

DB Boyle

Keyword(s):

Genetic Material ◽

Essential Element ◽

Fertility Control ◽

Vaccine Antigen ◽

Environmental Damage ◽

Pest Species ◽

European Settlement ◽

Animal Populations ◽

Feral Animals ◽

Feral Animal

A wide variety of vertebrates have been introduced into Australia during the 200 years of European settlement. Many have become pests causing significant environmental damage and having the potential to act as reservoirs of infectious diseases. Control of vertebrate pest species by fertility control is attractive on animal welfare grounds. Should exotic animal diseases become established in any of these feral animal populations vaccination would be an essential element in the control or eradication of disease. The only experience to date with vaccination of wildlife or feral animals has been the successful control of rabies in foxes in Europe by means of a live, attenuated rabies vaccine and a vaccinia-rabies recombinant vaccine. The feasibility of vaccination for disease control or fertility control in other vertebrate pests will depend on the development and evaluation of several vaccine vector strategies. The choice of vector, based on live viruses or bacteria, naked DNA coding for vaccine antigen or virus-like particles encapsidating genetic material coding for vaccine antigen, will depend on optimization of vector delivery strategies and immunogenicity of the vaccine antigen. Past experience from the vaccination of foxes against rabies suggests that rates of uptake of the vaccine bait and immunogenicity of the vaccine will be crucial factors in determining the success of other vaccines controlling disease or fertility.

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Horizontal Transmissible Protection against Myxomatosis and Rabbit Hemorrhagic Disease by Using a Recombinant Myxoma Virus

Journal of Virology ◽

10.1128/jvi.74.3.1114-1123.2000 ◽

2000 ◽

Vol 74 (3) ◽

pp. 1114-1123 ◽

Cited By ~ 62

Author(s):

Juan Bárcena ◽

Mónica Morales ◽

Belén Vázquez ◽

José A. Boga ◽

Francisco Parra ◽

...

Keyword(s):

Horizontal Transmission ◽

Myxoma Virus ◽

Transmissible Gastroenteritis Virus ◽

Hemorrhagic Disease ◽

Wild Rabbit ◽

Rabbit Hemorrhagic Disease ◽

Recombinant Viruses ◽

New Strategy ◽

Transmissible Gastroenteritis ◽

Capsid Protein Vp60

ABSTRACT We have developed a new strategy for immunization of wild rabbit populations against myxomatosis and rabbit hemorrhagic disease (RHD) that uses recombinant viruses based on a naturally attenuated field strain of myxoma virus (MV). The recombinant viruses expressed the RHDV major capsid protein (VP60) including a linear epitope tag from the transmissible gastroenteritis virus (TGEV) nucleoprotein. Following inoculation, the recombinant viruses induced specific antibody responses against MV, RHDV, and the TGEV tag. Immunization of wild rabbits by the subcutaneous and oral routes conferred protection against virulent RHDV and MV challenges. The recombinant viruses showed a limited horizontal transmission capacity, either by direct contact or in a flea-mediated process, promoting immunization of contact uninoculated animals.

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Habitat factors related to wild rabbit population trends after the initial impact of rabbit haemorrhagic disease

Wildlife Research ◽

10.1071/wr05107 ◽

2006 ◽

Vol 33 (6) ◽

pp. 467 ◽

Cited By ~ 27

Author(s):

Carlos Calvete ◽

Enrique Pelayo ◽

Javier Sampietro

Keyword(s):

Habitat Quality ◽

Population Trends ◽

Wild Rabbit ◽

Pest Species ◽

Predator Species ◽

Rabbit Population ◽

Habitat Factors ◽

Rabbit Haemorrhagic Disease ◽

Haemorrhagic Disease

The European wild rabbit (Oryctolagus cuniculus) is an introduced pest species in Australia and New Zealand. Rabbits have a devastating negative impact on agricultural production and biodiversity in these countries, and Rabbit Haemorrhagic Disease (RHD) is currently included in control strategies for rabbit populations. On the other hand, the European wild rabbit is a key native prey species in the Iberian Peninsula. Since the arrival of RHD, however, rabbit populations have undergone dramatic decreases and several predator species at risk of extinction are currently dependent on the rabbit population density. Therefore, from the point of view of biodiversity conservation, evaluating habitat correlates and trends of rabbit populations after the first RHD epizootic is of great interest to improve the long-term control or promotion of wild rabbit populations. We estimated the relationship between habitat factors and long-term population trends as well as the relationships between habitat factors and rabbit abundance 2 and 14 years after the arrival of RHD in several Iberian rabbit populations. We observed that only 26% of surveyed populations seemed to experience an increase in rabbit abundance over the last 12 years and that this increase was higher in the low-rabbit-abundance areas of l992, leading to high rabbit abundance in 2004. Our results suggested that short- and long-term impacts of RHD were related to habitat quality. The initial impact of RHD was higher in more suitable habitats, but increasing long-term population trends were positively related to good habitat quality.

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Effects on non-target animal populations of a rabbit trail-baiting campaign with 1080 poison

Wildlife Research ◽

10.1071/wr9910315 ◽

1991 ◽

Vol 18 (3) ◽

pp. 315 ◽

Cited By ~ 12

Author(s):

JC Mcilroy ◽

EJ Gifford

Keyword(s):

Vulpes Vulpes ◽

Oryctolagus Cuniculus ◽

New South ◽

New South Wales ◽

Control Measures ◽

Pest Species ◽

Target Animal ◽

South Wales ◽

Animal Populations ◽

Exotic Pest

Populations of non-target birds and mammals on a semi-cleared grazing property near Braidwood, New South Wales, did not appear to be affected by a trail-baiting campaign against rabbits, Oryctolagus cuniculus, using pellet bait and 1080 poison. Rabbit numbers were reduced by about 90% and those of the fox, Vulpes vulpes, another exotic pest, by about 75%. Populations of both pest species began recovering soon after the campaign, indicating the need for continued control measures.

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Field selectivity of a spinosad-poisoned bait toward target tephritids and non-target insects

Bollettino della Società Entomologica Italiana ◽

10.4081/bollettinosei.2014.11 ◽

2014 ◽

pp. 11-15 ◽

Cited By ~ 1

Author(s):

Marco Infusino ◽

Nino Iannotta ◽

Stefano Scalercio

Keyword(s):

Pest Control ◽

Ceratitis Capitata ◽

Negative Impact ◽

Control Strategies ◽

Field Trials ◽

Pest Species ◽

Wild Populations ◽

Target Species ◽

Key Points ◽

Insect Monitoring

One of the key-points in sustainable agriculture is to minimize the amount of pesticides inputs in agro-ecosystems increasing selectivity of active agents on target pests mainly. According to this perspective, control strategies utilising baits receive a growing interest. a spinosad-poisoned sugar-based bait, the so called GF-120 bait, utilised against diptera Tephritidae, recently appeared on the market. The toxicity of spinosad for non-target insects is demonstrated by several authors. However, the amount of pesticide applied is strongly reduced by using it with an attractive food-bait, even if field evidences on the selective attraction of this bait are missing. The aim of this paper is to evaluate the selectivity of GF-120 bait toward target and non-target insects under field conditions, focussing our attention on pollinators. Field trials were performed in a 20 years old olive orchard, where 12 baited and 12 unbaited traps were positioned for insect monitoring. The abundance of the most common orders of insects and target pest species Bactrocera oleae and Ceratitis capitata has been assessed. The main finding of this research is that many pollinators are not attracted by the bait, while target and non-target diptera are significantly attracted by the bait with the exception of Muscidae. The attraction toward a part of non-target diptera should be better explored in order to avoid negative impact on beneficial and non-target species. The need of pest control strategies safer for the environment and the wild populations of non-target organisms seems to be satisfied by the use of this bait.

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Myxomatosis in the Mallee region of Victoria, Australia

Journal of Hygiene ◽

10.1017/s0022172400025067 ◽

1978 ◽

Vol 81 (2) ◽

pp. 239-243 ◽

Cited By ~ 4

Author(s):

Rosamond C. H. Shepherd ◽

J. W. Edmonds ◽

I. F. Nolan ◽

A. Gocs

Keyword(s):

Late Summer ◽

Nutritional Stress ◽

Early Summer ◽

Myxoma Virus ◽

Direct Result ◽

Healthy Population ◽

Wild Rabbit ◽

Population Reduction ◽

In The Wild ◽

Limited Food

SummarySharp reductions in the wild rabbit (Oryctolagus cuniculus (L.)) population in the Mallee are associated with annual myxomatosis epizootics. The extent to which the population reductionsare the direct result of the epizootics varies with time of epizootic occurrence. All grazing animals in the Mallee are under nutritional stress each summer and autumn. When the epizootic occurs during the early summer heavy losses occur in a previously healthy population. Similar losses which occur in the late summer and autumn are the result of a nutritional stress – epizootic complex. The end result in each case is a population reduction of about 80%.This reduction occurs in a population which is the most resistant to myxomatosis known in Victoria and in association with epizooties caused by field strains of myxoma virus of moderate virulence only.The earlier summer epizootics are of considerable economic importance because they sharply reduce the pressure on the limited food available for other grazing animals.

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Managing problem wildlife in the ‘Old World’: a veterinary perspective

Reproduction Fertility and Development ◽

10.1071/r96090 ◽

1997 ◽

Vol 9 (1) ◽

pp. 17 ◽

Cited By ~ 25

Author(s):

M. Artois

Keyword(s):

Wildlife Management ◽

Native Species ◽

Animal Health ◽

Fertility Control ◽

Control Measures ◽

Pest Species ◽

Game Species ◽

Domestic Species ◽

Stray Dog ◽

Methods Of Control

This paper focuses on mammalian pest species mainly in Europe and Africa and on implications for animal health, human safety, wildlife management and animal welfare. Three examples of problem species are presented: the wild boar (Sus scrofa), the stray dog (Canis familiaris) and the red fox (Vulpes vulpes). Several species are reservoirs or vectors of transmissible diseases of man and of economically valuable domestic species. The control of these and other infections and the limitation of the nuisance or damage caused by these pest species involves lethal or non-lethal methods which are briefly reviewed. Some control measures require veterinary expertise, and veterinary involvement in managing problem species is likely to increase. With regard to fertility control, methods are considered which will allow an appropriate choice of the best technique for the management of problem animals in various habitats. For desirable native species, traditional methods of control, especially hunting in the case of game species, is preferable to contraception. For exotic or feral species, control of fertility seems to be a worthwhile option.

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