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Sperm-based contraceptive vaccine for the wild rabbit - VC0224

One possible method for humane rabbit control is the use of an oral contraceptive vaccine consisting of a microparticle-encapsulated peptide antigen conjugated to an appropriate carrier protein; significant inhibition of fertility was obtained when laboratory female rabbits were fed such a vaccine. In addition, a novel enhancer of particle uptake in the gastrointestinal tract was discovered and designated the mucosal antigen delivery protein (MADP). This study will aim to further validate these findings with a series of large-scale trials evaluating the performance and effects of sperm-based vaccine and the characteristics and use of MADP. The study will be composed of 6 specific objectives outlined as follows, together with ways in which they might be achieved: 1. Confirmation and verification of the reduction in fertility of female laboratory rabbits administered sperm-based contraceptive vaccine with a large-scale fertility trial and a detailed investigation of the correlation of immune responses both in serum and reproductive tract fluids. 20 treated female rabbits administered complete vaccine for 18 weeks will be mated with bucks and assessed for fertility at 21 weeks; 20 control females (vaccine without antigen, vaccine with microparticles alone) will also be monitored; 2. Determination of the complete biochemical and genetic characteristics of MADP. A series of analytical techniques (including ion-exchange chromatography and hydrophobic interaction chromatography) will be used to characterise MADP. Proteins associated with MADP-active fractions will be analysed by mass spectroscopy and amino acid sequencing after electrophoretic separation; 3. Investigation of the use of purified MADP, along with improved microparticle technology to further enhance vaccine efficiency. Oral administration of MADP with vaccine will be undertaken in laboratory rabbits. Functional responses in terms of mucosal and systemic antibody production will be measured by ELISA and by immunohistochemistry and compared with responses to microparticles in the absence of MADP. Mucosal immune responses will be evaluated in the saliva, and genital and gastrointestinal tract section; 4. Evaluation of any possible toxic effects of multiple applications of vaccine in laboratory rabbits. A long term trial will be conducted to monitor the health status of 8 rabbits (4 female, 4 male) administered the vaccine every month. At the end of the trial, tissues will be taken at autopsy for histopathological analysis; 5. Investigation of the species-specificity of sperm-based vaccine and in particular the effects of antiserum from immunised rabbits on sperm-egg interactions in vitro in the hare (Lepus europaeus). Gametes from wild caught hares will be used in cross-species in vitro fertilisation assays; and 6. Monitoring and evaluation of serum and reproductive tract immune responses to contraceptive vaccine in group-housed female wild rabbits. Overall results of the study will be applied directly to the development of a contraceptive vaccine for the control of wild rabbits.
Project Documents
• Final Report : Sperm-based contraceptive vaccine for wild rabbit   (77k)
Time-Scale and Cost
From: 2000

To: 2002

Cost: £255,661
Contractor / Funded Organisations
Babraham Institute, Cambridge (BBSRC), Sheffield University, Molecular Biology
Pest and Weed Control              
Pest Control              
Plants and Animals              
Wildlife Management              
Fields of Study
Wildlife Management