TICKS AND TICK-BORNE DISEASE SIGNIFICANTLY AFFECT LIVESTOCK WORLDWIDE. TICK FEEDING CAN REDUCE MILK PRODUCTION, REDUCED WEIGHT GAIN, DAMAGE TO HIDES, ANEMIA, AND EVEN DEATH. ESTIMATES HAVE CALCULATED ECONOMIC LOSSES OF AROUND $18.7 BILLION WORLDWIDE ANNUALLY. FURTHERMORE, TICK-BORNE DISEASES, SUCH AS BOVINE ANAPLASMOSIS, CAN RESULT IN SUBSTANTIAL ECONOMIC LOSSES. CURRENT TICK CONTROL MEASURES ARE FOCUSED ON THE USE OF SYNTHETIC ACARICIDES.NEVERTHELESS, THE EMERGENCE OF RESISTANCE TO SEVERAL ACARICIDES IN TICK POPULATIONS HAS BECOME A SOURCE OF CONCERN. THUS, INCREASED INTEREST HAS EMERGED IN FINDING ALTERNATIVE APPROACHES FOR THE CONTROL OF TICK POPULATIONS. ONE OF SUCH APPROACHES IS THE DEVELOPMENT OF ANTI-TICK VACCINES. ALTHOUGH SOME SUBUNIT VACCINES HAVE SHOWN PARTIAL PROTECTION, POLYMORPHISM IN PROTEIN SEQUENCE BETWEEN TICK POPULATIONS AND TICK SPECIES REDUCES THEIR EFFICIENCY. THIS PROJECT AIMS TO EXAMINE THE POTENTIAL USE OF TICK SALIVARY GLANDS- AND MIDGUT-DERIVED EXTRACELLULARVESICLES AS VACCINE CANDIDATES AGAINST TICKS. WE WILL ALSO IDENTIFY ANTIGENIC PROTEINS WITHIN THESE VESICLES. WE WILL EVALUATE AND IDENTIFY PROTEINS PACKED IN AND WITHIN TICK EXTRACELLULAR VESICLES THAT LEAD TO IMMUNOGENIC RESPONSES IN CATTLE AND DEER USING TWO DIFFERENT TICK SPECIES: THE CATTLE FEVER TICK AND THE LONE STAR TICK. THESE PROTEINS WILL BE USED TO GENERATE ARTIFICIAL VESICLES THAT CAN BE MASS-PRODUCED TO COMMERCIALIZE AN ANTI-TICK VACCINE THAT IS PROTECTIVE AGAINST DIFFERENT TICK SPECIES. EFFECTIVE TICK VACCINES WILL DECREASE THE IMPACT THAT TICKS HAVE ON CATTLE AND LESSEN THE TICK-BORNE DISEASE BURDEN. THIS KNOWLEDGE CAN THEN BE APPLIED TO OTHER SYSTEMS, POTENTIALLY IMPACTING ANIMAL AND HUMAN HEALTH.