Post-doctoral staff member at University fo Pretoria, South Africa. My current research focus is on the development on immunocontraceptive vaccines for use in female dogs during rabies vaccination campaigns utilising a recombinant virus platform.
Domestic dogs are responsible for the vast majority of human rabies cases. To eliminate rabies from a given population, two components are crucial namely mass vaccination of dogs and provision of post-exposure prophylaxis (PEP) to bite victims. The cost of PEP prohibits the reliance on this alone for rabies control in endemic areas. To achieve the recommended 70% vaccination coverage of dogs in developing countries can be difficult. Previous research conducted during my post-graduate student career evolved around the epidemiology of rabies lyssavirus and other African lyssaviruses. This provided me with crucial background and context of rabies to enable me to recognise current shortcomings. The high population turnover rates in free-roaming dogs is a major factor that influences the efficacy and cost of vaccination programs. As a population management intervention surgical sterilization is cost-prohibitive in developing countries, while chemical sterilization presents many difficulties associated with safety and acceptance of such practices. Immunocontraceptives may offer an ideal, non-permanent mechanisms to interrupt breeding cycles and contribute to population management. In light of this disease burden my recent research has focused on developing recombinant immunocontraceptive vaccines for use in female dogs during annual rabies vaccination campaigns. Various recombinant DNA technologies were employed to develop candidate vaccines that were evaluated in mice and encouraging results were obtained from 2 recombinant Human adenovirus constructs. These candidate vaccines elicited significant immune responses in mice. As such expansion of the project will build on the developments outlined above to enhance the immunogenicity of these vaccines though various approaches such as the inclusion of additional immune stimulatory motifs, adjuvants and refinement of vaccine production techniques. Furthermore, these strategies would require evaluation of the effect on immunogenicity in target species. The paucity of humane alternatives for population management as well as the global public health burden of rabies, serve as dual incentives for the continued research and development of novel biologics. The recombinant virus platform that has been established and skills acquired through the development of contraceptive vaccines open opportunities for collaboration with other research groups towards the development or refinement of other vaccine candidates such as the simian adenovirus vectored rabies vaccine developed by Wang et al. (PLoS Negl Trop Dis 12(10): e0006870) or ONRAB currently used for oral vaccination of wildlife against rabies (Gilbert et al. Vaccine. 2018 Aug 6;36(32 Pt B):4919-4926), that can address other current needs/shortcomings such as vaccines for human PEP use. These developments hold the promise of possible long-term solutions to the prevention for of significant infectious diseases. This represents long-term research interests that will allow myself as well as future members of my research group the opportunity to positively impact on the control of rabies.