Protective immunity against tick infestation in cattle vaccinated with recombinant trypsin inhibitor of Rhipicephalus microplus

► Tested vaccine with recombinant Kunitz protein for cattle tick immunoprotection. ► Larval R. microplus trypsin inhibitor was produced in yeast expression system. ► Immunization afforded 32% efficacy against cattle tick infestation. ► Larval R. microplus trypsin inhibitor resembles three-headed Kunitz protein BmTI-6.