PSV-1 A Subcutaneous Ear Implant to Deliver an Anaplasmosis Vaccine to Dairy Steers. (30th November 2020)

• Record Type: Journal Article
• Authors: Curtis, Andrew K; Reif, Kathryn; Kleinhenz, Michael; Martin, Miriam S; Skinner, Brandt; Kelly, Sean; Jones, Douglas; Reppert, Emily; Montgomery, Shawnee; Narasimhan, Balaji; Anantatat, Tippawan; Jaberi-Douraki, Majid; Coetzee, Johann
• Is Part Of: Journal of animal science. Volume 98(2020)Supplement 3
• Page Start: 156
• Page End: 157
• Publication Date: 2020-11-30
• Subjects: Anaplasmosis -- vaccine -- cattle; Livestock -- Periodicals; Livestock; Electronic journals; Periodicals; 636.005
• DOI: 10.1093/jas/skaa054.275
• Languages: English
• ISSNs: 0021-8812

Abstract

Abstract: Bovine anaplasmosis is the most prevalent tick-transmitted disease of cattle worldwide and a major obstacle to beef production. The objective of the study was to test the ability of a single-dose delivery platform to produce long-lasting immunity against anaplasmosis infections. Twelve Holstein steers were administered a 3-stage, single-dose vaccine against Anaplasma marginale major surface protein 1a. The vaccine consisted of a soluble vaccine administered subcutaneously for immune priming, a biodegradable polyanhydride depot for intermediate slow-release of the vaccine for boosting the immune response, and an immune-isolated vaccine platform for extended antigen release deposited subcutaneously in the ear. Six calves were randomly assigned to two vaccine constructs that featured rods and implants containing a combination of two adjuvants (DEAE-Dextran and Quil-A). The remaining 6 calves were randomly assigned to two vaccine constructs that featured rods and implants containing the same adjuvant (DEAE-Dextran or Quil-A). Twenty months post-implantation, calves were challenged with Anaplasma marginale stabilate and were monitored weekly for signs of fever, decreased packed cell volume (PCV) and bacteremia. Outcome variables (fever, PCV, bacteremia) were analyzed using a linear mixed model (PROC GLMMIX; SAS University Edition v9.04.01, SAS Institute, Cary, NC). Two-tailed chi-squared tests were used to compare need for antibiotic intervention between vaccine constructs. Calves within the combination adjuvant construct group (DEAE-D and Quil-A) exhibited significantly (P = .006) higher PCV than calves within the single adjuvant construct group (DEAE-Dextran or Quil-A). Likewise, calves within the combination adjuvant group required significantly (P = .014) fewer antibiotic interventions compared with calves in the single adjuvant group. Findings of this study suggest that calves exhibited significantly diminished clinical signs of anaplasmosis when vaccine was delivered with a combination of adjuvants as opposed to a single adjuvant in a single-dose delivery platform.