East Coast fever, which is caused by Theileria parva infection in cattle, is of major economic importance in eastern and central Africa. Until recently, the only available method of immunization against East Coast fever was the infection with live sporozoites and simultaneous treatment with a long-acting oxytetracycline. This method has two major disadvantages: (I) it uses live organisms; and (2) the immunity engendered is parasite strain specific. In this article, Antony Musoke, Vishvonath Nene and Subhosh Morzoria review the progress made in developing an alternative method o f immunization based on a defined sporozoite antigen.