Submitted to: Journal of Medical Entomology
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 5/22/1998
Publication Date: N/A
Interpretive Summary: Psoroptes ovis (Hering), the sheep scab mite, is an economic pest of cattle and sheep production throughout the world. The problem in the United States has been reduced with chemical treatment practices; however, anticipating the inevitable development of resistance of the mite to chemicals we continue the development of novel and alternative control technologies. Vaccine augmented host immunity to the mite offers an environmentally safe technology for the control of this mite on cattle. In this study, a vaccine was formulated with proteins isolated from the mite. Calves vaccinated with these proteins had 8 of 14 calves free of scabies lesions 8 weeks after a challenge infestation. A self-grooming behavioral response was presumed to be the significant effector in protecting the calves. The grooming response of vaccinated calves was heightened by an allergic, itchy, response to mite allergens.
Technical Abstract: Psoroptes ovis is an economic pest of cattle and sheep throughout the world. Although current chemical treatment practices have reduced the incidence of cattle scabies, the parasite persists in the U.S. Anticipating the inevitable development of acaricide resistance, and attempting to reduce our reliance upon pesticides, researchers continue the edevelopment of novel and alternative control technologies. Vaccine- augmented host resistance is an environmentally safe technology that offers an alternative control approach for P. ovis. In this study potential vaccine candidate immunogens were identified and evaluated in a vaccine challenge trial. Calves vaccinated with a partially purified fraction of P. ovis soluble proteins had 8 of 14 calves free of palpable lesions 8 weeks after a challenge infestation. A self-grooming behavioral response elicited by a pruritic immediate-type allergic reaction was believed to be the significant effector in protecting the vaccinated calves from a clinical P. ovis infestation.