African Horse Sickness (AHS) Vaccine
African Horse Sickness (AHS) is a highly-infectious vector-borne disease that affects horses. It is endemic to Africa and all nine serotypes are present in South Africa and has a mortality rate of between 70-90%. The Biopharming Research Unit at UCT has developed a novel vaccine candidate that is created from a virus-like particle (VLP). The VLP is produced in a plant and is able to elicit an immune response, but it is not infectious so there is no fear of it reverting to a virulent strain (a possibility when live attenuated viruses are used as vaccines). Currently, the commercially available vaccine does not protect against serotypes 5 and 9 and this is the core focus of the technology development.
The hope is to produce a multivalent vaccine that is able to provide protection against all 9 serotypes of African Horse Sickness, or as a minimum to provide vaccines that will augment the currently available vaccine that is marketed in southern Africa, but that does not provide protection against serotypes 5 and 9. Whilst there is a significant opportunity in Africa, due to warming conditions, there have been incidents in Spain, the Middle East, India and Turkey.
The plant-made virus-like particle (VLP) vaccine that has been developed at UCT is able to elicit an immune response, but it is not infectious so there is no fear of it reverting to a virulent strain (a possibility when live attenuated viruses are used as vaccines). Territories that do not have a specific serotype, or cases of AHS yet, may wish to proactively protect their equines, but fear using attenuated live vaccines; the VLPs offer a solution to this.
The UCT AHS vaccine will provide protection against all serotypes using Virus-Like Particles (VLPs), to elicit the immune response, enabling the vaccine to be used in territories where particular serotypes (or AHS) are not currently present. Thus providing a full-spectrum protection, which current commercial vaccine products are not doing.
The plant-based production platform enables the different serotypes to be produced rapidly and also multivalent vaccines to be produced.
The UCT Biopharming Research Unit (BRU) (http://www.mcb.uct.ac.za/mcb/BRU-home) has over 15 years of experience in the production of proteins in tobacco plants through transient genetic modification. They have successfully licensed their Human Papillomavirus (HPV) patent families to two different international pharmaceutical companies and a UCT spin-off company, Cape Bio Pharms, is currently producing reagents, based on the platform technology.
BRU is currently working on two orbivirus vaccines that are related in that the viruses that cause Bluetongue disease (BTV) and African Horse Sickness (AHS) are spread by the same midges. A number of patents are held by UCT relating to these vaccines and the technology is at the point of target animal trials and funded projects are ongoing.