- The CRC Fertility Control Vaccine Strategy
- Fig 1. CRC Strategy and Supporting Expertise and Interactions
- The Future
- References
Overview of CRC Strategy: Development of Fertility Control Vaccines for Possum Biocontrol
John Roger
Cooperative Research Centre for Conservation & Management of Marsupials
Marsupial CRC, PO Box 1927 Macquarie Centre, NSW, Australia 2113
The aim of CRC possum biocontrol research is orally active, environmentally safe, field deliverable vaccines that produce long-term compromise of fertility (Cowan, 2001; Ramsey et al, 2001). Our resproductive targets fall into three categories;
- Under testing - Egg coat proteins (ZPs) which have been proven in many mammals (Duckworth et al., 2001),
- Under development - Sperm antigens and ZP epitopes which offer more specific targeting (Harris et al, 2001), and
- Strategic research on new targets in the female tract and its processes leading to fertilization (Molinia et al, 2001, Rodger et al, 2001).
The vaccine delivery systems the CRC is focused on are all non-disseminating (non-spreading). Although gene technology is a feature of our research, and the production of vaccines, the final products for field use will be non-viable and thus not GMOs in the normal sense. A feature of our work is international collaboration this brings the CRC access to valuable vaccine intellectual property and additional resources. Our main focus is on; 1) Plant-based vaccines (carrot, potato), 2) Bacterial ghosts (non-GMOs), and 3) Virus-like particles (VLPs)(Duckworth et al, 2001; Kay, 2001)
The CRC's possum biocontrol related research is supported by a transTasman funding mix:
- CRC Program and CRC parties contributions;
- Landcare Research for additional work on product development and testing;
- NZ Possum interests - in particular MAF Policy, Foundation for Research Science and Technology and the Animal Health Board.
The CRC Fertility Control Vaccine Strategy
Our approach is highly multi-disciplinary and collaborative. Fig 1 below outlines how basic research in marsupial biology and immunology provides the knowledge base and technologies needed for vaccine development. Through international collaborations we have accessed two very promising non-disseminating oral vaccine technologies the plant vaccines and bacterial ghosts. The CRC is also supporting research into virus-like particles as an alternative strategy. None of these technologies are proven under field conditions so the CRC is developing these delivery systems in tandem rather than attempting to pick a winner.
A key factor in carrying this product development further is the vaccine testing facility and expertise which has been established by Landcare Research at Lincoln. This extensive facility and the standard operating procedures and skilled staff now in place means that promising target antigens can be reliably tested using natural breeding and CRC developed assisted breeding techniques. Through Landcare's ecology expertise the CRC has been able to undertake field experiments and modeling to better define the attributes of an effective fertility control product and how they might be used. Finally through our growing links with possum control interests the CRC is in a position to move to field trials once proof of product is established in a limited field trial situation. Our goal for achieving this is 3-4 years based on current progress with possums under animal house conditions. The CRC has not the expertise or resources to cover all the activity areas outlined above and thus it draws on an extensive network of research and industry/user support to realise its goals.
Fig 1. CRC Strategy and Supporting Expertise and Interactions
The Future
Although short-listed, the CRC was unsuccessful in its bid for a second round of funding from the Australian Governments CRC program in 2000. The CRC has funds to continue its work till mid-2003 which will allow us to rebid in the next round in 2002. Part of our strategy is a spin-off company to carry forward the possum control work to proof of product in a limited field trail as discussed earlier. The CRC's possum focused work is thus reasonably secure for the immediate future. The main challenge is to maintain the base of under pinning research that is needed to carry our work through to a field effective control system for the possum and to maintain the CRC's Australian focused work in marsupial management and conservation.
References
Cowan, P. 2001. Immunologically based fertility control for possums - is non-response an issue? This issue.
Duckworth, J.D; et al 2001.
Harris, M. S.; et al. 2001. Identification of new antigen targets and molecular dissection of antigenicity for possum immunocontraception. This issue.
Kay D. 2001. Recent development in marsuial immunology and key issues in vaccine development. This issue.
Molinia, F.C.; et al. 2001. In vitro and in vivo models of key reproductive events as tools for possum biocontrol. This issue
Ramsey, D. et al. 2001.
Rodger, J.C.: 2001. Recent developments in IVF and oviduct biology: new experimental tools & biocontrol targets. This issue
Contact for Enquiries
Manager, Strategic Science Team
MAF Biosecurity New Zealand
PO Box 2526
Wellington
NEW ZEALAND
Phone: +64 4 894 0115
Fax: +64 4 894 0731
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