Improvement of Theileria parva sporozoite vaccine against East Coast fever
East Coast fever (ECF), a tick-borne disease of livestock in Africa, causes economic losses of approximately USD$1 billion annually due to the high mortality rate of infected animals. Animals that do recover become parasite carriers and can be sources of further infection. The losses affect farmers directly, but ECF also impacts other industries such as mining and commerce, which often use ox-drawn transport.
Why is an improved ECF vaccine necessary?
Vaccination is the most effective method to control ECF. However, the current vaccine is expensive and cumbersome to produce and administer. This is because it uses a method of vaccination known as “infection and treatment” that requires the inoculation of cattle using live Theileria parva parasites, and simultaneous treatment of the symptoms with expensive antibiotics. It also uses a large number of cattle in vaccine production and it is difficult to standardize, store, and distribute.
Developing an innovative solution
This innovative approach will have researchers feeding the ticks on an artificial membrane containing bovine blood, rather than on cattle and rabbits as has traditionally been the case. This will reduce the number of animals being used in vaccine production. It will also allow for the concentration of Theileria parva sporozoites injected by the infected ticks to be better quantified when determining vaccine doses. Researchers will also attempt to reduce the virulence of the parasites by zapping them with a measured dose of radiation. By reducing the sporozoite virulence, the vaccine could possibly be administered without the need for antibiotics.
The expected outcome of this project is a simplified and standardized vaccine production process that will use fewer animals and eliminate the need for concurrent antibiotic treatment. This will result in cheaper and more affordable ECF vaccines for smallholder farmers. The improved production process will also be transferred to the African Union’s Pan-African Veterinary Vaccine Centre to allow for external quality control of the vaccine when manufacturers adopt the improved production process.
This project is a collaboration between the Animal Disease Research Unit of the United States Department of Agriculture, ClinGlobal Ltd., and the African Union Centre for Ticks and Tick-Borne Diseases in Malawi.
- Duration: 30 months
- Budget: CA$1 million