The biology of Theileria parva and control of East Coast fever—Current status and future trends

Tremendous progress has been made over the last ten years on East Coast fever (ECF) research. Publication of a reference genome sequence of Theileria parva, the causative agent of ECF, has led to a more thorough characterization of the genotypic and antigenic diversity of the pathogen. It also facilitated identification of antigens that are targets of bovine major histocompatibility complex class I restricted cytotoxic T-lymphocytes (CTLs), induced by a live parasite-based infection and treatment method (ITM) vaccine. This has led to improved knowledge of epitope-specific T-cell responses to ITM that most likely contribute to the phenomenon of strain-specific immunity. The Muguga cocktail ITM vaccine, which provides broad-spectrum immunity to ECF is now a registered product in three countries in eastern Africa. Effort is directed at improving and scaling up the production process to make this vaccine more widely available on a commercial basis in the region. Meanwhile, research to develop a subunit vaccine based on parasite neutralizing antibodies and CTLs has been revived through convening of a research consortium to develop proof-of-concept for a next generation vaccine. Many new scientific and technical advances are facilitating this objective. Hence, the next decade promises even more progress toward an improved control of ECF.