Immunization of bovines with an aspartic proteinase precursor isolated from Boophilus microplus eggs

The capacity of the Boophilus Yolk pro-Cathepsin (BYC) to induce a protecti ve immune response in cattle against Boophilus microplus infestation was te sted by vaccination experiments and by inoculation of monoclonal antibody ( MAb) against BYC into fully engorged tick females. In immunization experime nts the measurement of various biological parameters demonstrated a partial protection against B. microplus. A continuous decrease in the levels of sp ecific antibodies was observed over 11 months when six bovines were maintai ned in field conditions. The inoculation of the MAb into tick females produ ced a dose-dependent decrease in oviposition and survival of the ectoparasi te compared to the control. (C) 1998 Elsevier Science B.V. All rights reser ved.