Potential effect of prior raccoonpox virus infection in raccoons on vaccinia-based rabies immunization.
BACKGROUND
The USDA, Wildlife Services cooperative oral rabies vaccination (ORV) program uses a live vaccinia virus-vectored (genus Orthopoxvirus) vaccine, Raboral V-RG (V-RG), to vaccinate specific wildlife species against rabies virus in several regions of the U.S. Several naturally occurring orthopoxviruses have been found in North America, including one isolated from asymptomatic raccoons (Procyon lotor). The effect of naturally occurring antibodies to orthopoxviruses on successful V-RG vaccination in raccoons is the focus of this study.


RESULTS
Overall, raccoons pre-immunized (n = 10) with a recombinant raccoonpox virus vaccine (RCN-F1) responded to vaccination with V-RG with lower rabies virus neutralizing antibody (VNA) titers than those which were not pre-immunized (n = 10) and some failed to seroconvert for rabies VNA to detectable levels.


CONCLUSIONS
These results suggest that the success of some ORV campaigns may be hindered where raccoonpox virus or possibly other orthopoxvirus antibodies are common in wildlife species targeted for ORV. If these areas are identified, different vaccination strategies may be warranted.
Root
J Jeffrey
JJ
United States Department of Agriculture, Wildlife Services, National Wildlife Research Center, Fort Collins, CO 80521, USA. jeff.root@aphis.usda.gov
McLean
Robert G
RG
Slate
Dennis
D
MacCarthy
Kathleen A
KA
Osorio
Jorge E
JE
D000818:Animals; D000914:Antibodies, Viral / Q000096:biosynthesis / Q000276:immunology*; D004197:Disease Reservoirs; D018155:Orthopoxvirus / Q000276:immunology*; D011213:Poxviridae Infections / Q000276:immunology / Q000662:veterinary*; D011818:Rabies / Q000276:immunology / Q000517:prevention & control / Q000662:veterinary*; D011819:Rabies Vaccines / Q000276:immunology*; D011820:Rabies virus / Q000276:immunology; D011821:Raccoons / Q000276:immunology*; D014611:Vaccination / Q000662:veterinary; D014614:Vaccines, Synthetic / Q000276:immunology; D014616:Vaccinia virus / Q000235:genetics / Q000276:immunology
D000914:Antibodies, Viral; D011819:Rabies Vaccines; D014614:Vaccines, Synthetic