Submitted to: Vaccine
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 9/12/2005
Publication Date: 9/29/2005
Citation: Olsen, S.C., Christie, R.J., Grainger, D.W., Stoffregen, W.C. 2005. Immunologic responses of bison to vaccination with Brucella abortus strain RB51: Comparison of parenteral to ballistic delivery via compressed pellets or photopolymerized hydrogels. Vaccine. 24(2006):1346-1353. Interpretive Summary: Brucella abortus is a disease that causes abortion and associated economic losses in infected cattle herds. The infection of bison with Brucella abortus in Yellowstone National Park pose a risk to the completion of the Brucellosis Eradication Program for cattle. For vaccination of bison within Yellowstone National Park, a remote vaccination method that doesn't require capture of bison is needed. Development of a protective, remotely delivered vaccine would be beneficial in resolving the controversy caused by brucellosis in bison. In this study, we evaluated SRB51 hydrogels as a vehicle for preparing ballistic bullets for vaccinating bison and compared immunologic responses. Our data suggest that the new polymer stimulates better immunologic responses than the previous method of ballistic bullet preparation but is still less than hand vaccination. This data will be of benefit to the National Park Service and the states of Montana, Wyoming, and Idaho in their efforts to resolve the brucellosis problem in the Yellowstone National Park bison. When combined with efficacy data, demonstration that a hydrogel biobullets induce protective immunologic responses will provide a tool for enhancing immunity and reducing transmission of brucellosis in bison. An efficacious vaccine for bison will help prevent transmission of brucellosis to cattle herds and assist in the completion of the Brucellosis Eradication Program.
Technical Abstract: This study compared responses of bison calves to 10(10) CFU of Brucella abortus strain RB51 (SRB51) delivered by parenteral or ballistic methods. Two types of biobullet payloads were evaluated; compacted SRB51 pellets or SRB51 encapsulated in photopolymerized poly(ethylene glycol) hydrogels. Bison were vaccinated with saline, parenteral SRB51 alone, or in combination with Spirovac(TM),or ballistically with compressed SRB51 or hydrogel biobullets. Bison parenterally vaccinated with SRB51 had greater (P<0.05) immunologic responses when compared to control bison. Co-administration of Spirovac(TM) as an adjuvant did not influence immunologic responses. As compared to compressed SRB51 biobullets, ballistic vaccination with hydrogel biobullets increased cellular immune responses at some sampling times. Parenteral vaccinates tended to have greater antibody and gamma-IFN responses when compared to ballistic vaccinates. Our data suggests that parenteral vaccination induces the greatest immunologic responses, and hydrogel biobullets induce greater responses than compressed SRB51 biobullets.