Oral Vaccination of White-Tailed Deer Using a Recombinant Bacillus Calmette-Guérin Vaccine Expressing the Borrelia burgdorferi Outer Surface Protein A: Prospects for Immunocontraception

PROBLEM: Reduction of excess numbers of white‐tailed deer (Odocoileus virginianus) is a prime example of a potential use for immunocontraception as a means of wildlife population management. Oral vaccination appears to be the most pragmatic way to deliver immunocontraceptive vaccines to free‐roaming populations of deer, but there was little, if any, prior evidence that oral vaccination is a viable concept in deer. METHOD OF STUDY: We used live Bacillus Calmette‐Guérin (BCG) in a recombinant form (rBCG), which expressed Borrelia burgdorferi outer surface protein A, to test whether deer vaccinated orally with a specific antigen expressed in a live vector produce detectable antibody titers. RESULTS: The data indicate that oral vaccination of deer with an expressed antigen is feasible, as demonstrated by peak antibody titers to the expressed antigen. Also, peak titers measured by enzyme‐linked immunosorbent assay were highest in orally vaccinated deer: 1600 in deer vaccinated by injection and 6400 in those vaccinated orally. CONCLUSIONS: The results of this study demonstrate that it is feasible to vaccinate deer orally with a live vector.