DEVELOPMENT OF CONVENTIONAL SUBUNIT VACCINES FOR ANAPLASMOSIS AND BABESIOSIS

Tick-borne hemoparasitic diseases of cattle continue to impact the bee f industry throughout a large portion of the world. A substantial amou nt of research is currently focused on development of improved vaccine s. The two main approaches being followed are: (1) use of conventional inactivated or native protein subunit vaccines, and (2) development o f recombinant DNA technology for expression of selected immunogens. Re combinant or synthetic peptide based vaccines hold promise owing to th e exquisitely defined nature of the product. However, the development is long-term, and will require extensive testing and risk assessment b efore field trials can be considered. Until then, more conventional su bunit immunogens may offer an attractive alternative, and can be defin ed immunologically better than before. This paper reviews progress in the development of improved vaccines for anaplasmosis and babesiosis w ith an emphasis on the characterization of culture-derived babesial ex oantigens. Both in vitro and in vivo information is presented.