multicomponent subunit vaccine against ECF that could be shown to be protective to cattle in laboratory trials. The project’s long-term goal was to generate a safe, efficacious affordable and easily deliverable ECF vaccine in partnership with a commercial company.
The key to success was identifying antigens that caused an immune response in the host cattle. This was to be pursued by sequencing the Theileria parva genome, cloning individual genes from the parasite, subjecting them to immunological assays, and determining which genes code for antigens are likely to confer immunity in the host cattle. The successful subunit vaccine would be one that incorporated sections of the Theileria parva DNA that, when injected into cattle, would confer immunity without infecting them with ECF.
Success required a range of expertise and resources. So, beginning in 1999, ILRI set out to develop a global partnership to sequence the Theileria parva and conduct research that would lead to the development of an effective subunit vaccine. Beginning in 2001, ILRI enlisted the participation of The Institute for Genome Research (U.S.A.), a global leader in genome sequencing, along with the Ludwig Institute of Cancer Research, the University of Victoria (Canada), Oxford University (UK), the Centre for Tropical Veterinary Medicine (UK), the Weizmann Institute of Science (Israel), and the Kenya Agricultural Research Institute. In the same year, ILRI enlisted the expertise of Merial Ltd., a global leader in the animal health field, to draw on the company’s experience in field of vaccine development and product deployment.
With Merial’s participation, the project team was able to develop an experimental vaccine. But while the testing with live cattle did generate the desired immune response—protection against ECF in cattle—the response occurred in only 30 percent of the cattle tested. Without this critical proof of concept, further partnership-based research effectively came to an end in 2007.
Despite these discouraging outcomes, research on an ECF vaccine continues. Under the leadership of the Global Alliance for Livestock Veterinary Medicines (GALVmed), efforts are underway to form a new consortium to continue to the research and secure funding.
Importantly, the project also generated several unintended consequences that will likely promote further research on an ECF vaccine. First, the project has encouraged several organizational innovations (e.g., new approaches to contracting, communicating, and intellectual property management) within ILRI and its partners to help bridge the gap between public and private sector researchers in future partnerships. Second, the project has put forth methodologies of vaccine antigen identification and evaluation that several research organizations are exploring, thus validating the project’s work and laying the ground for continued investment in ECF vaccine development.