Helminths (including anthelmintic resistance) roadmap:
Vaccines
Roadmap for nematode vaccine development
Download Nematode Vaccine Roadmap7
Vectored vaccines
Development of a vectored vaccine
Research Question
- Using a replicating organism to give enhanced exposure to protective antigens and optimal delivery to the correct arm of the host’s immune system.
- Attempting to avoid issues (folding/conformation/post-translational modifications) of recombinant protein-based vaccines
Research Gaps and Challenges
- If the same organism (vector) is to express the protective antigens of several parasites it may need to have a relatively large genome.
- Production of complex antigens from multicellular organisms.
- That the expressed antigen has the correct conformation.
- That revaccination doesn’t result in rapid elimination of the vector.
- That an appropriate vector is available for the livestock species being immunised.
- That the chosen vector stimulates the correct arm(s) of the immune response.
- Regulatory and consumer issues regarding GMOs.
- Potential pathogenicity/reversion of vector.
Solution Routes
- Development of a range of genetically modified organisms expressing protective antigens of one or more parasite species, either as a secreted entity or as a surface molecule.
- Epitope mapping of antigens to reduce the complexity and size of the inserted genes for expression.
Dependencies
- Identity of a suitable vector (e.g. Trypanosoma theileri or autologous retrovirus).
- Identity of protective antigens and their genetic sequences.
- Identity of correct protective immune response.
State Of the Art
- Adenovirus and canary pox virus widely used as vectors for other pathogens.
- Eimeria system in hens (Tomley et al) – some success (Pastor-Fernández et al 2018 IJP 48, 505-518
- Trypanosoma system (Matthews et al., 2016) – not yet proven
Projects
What activities are planned or underway?
Improving the performance of forage legumes through the use of optimal symbiotic partners using the example of sainfoin (Onobrychis viciifolia)
Planned Completion date 31/12/2023
Source Countries:
Denmark
Development of a web application for the risk assessment of the worm load of free-range laying hens (Wurmfrei)
Planned Completion date 31/12/2026
Source Countries:
Denmark