FIELD TRIALS OF ONTARIO RABIES VACCINE BAIT IN THE NORTHEASTERN USA, 2012–14

Authors

Amy Gilbert, APHIS, WS, NWRCFollow
Shylo R. Johnson, APHIS, WS, NWRC
Kathleen M. Nelson, USDA, APHIS, WSFollow
Richard B. Chipman, USDA, APHIS, WSFollow
Kurt C. VerCauteren, APHIS, WS, NWRCFollow
Timothy P. Algeo, USDA, APHIS, WS
Charles E. Rupprecht, LYSSA LLC
Dennis Slate, USDA, APHIS, WS

Date of this Version

2018

Citation

Journal of Wildlife Diseases, 54(4), 2018, pp. 790–801

Comments

Copyright Wildlife Disease Association 2018

This document is a U.S. government work and is not subject to copyright in the United States.

DOI: 10.7589/2017-09-242

Abstract

In the US, rabies virus (RV) has been enzootic in raccoons (Procyon lotor) since the late 1940s. Oral rabies vaccination (ORV) was implemented in the 1990s to halt the spread of raccoon RV and continues to be used as a wildlife management tool. Our objective was to evaluate a recombinant human adenovirus–rabies virus glycoprotein vaccine in northern New York, Vermont, and New Hampshire over a 3-yr period, using changes in RV neutralizing antibody (RVNA) seroprevalence in raccoon populations as an immunologic index of ORV impact. Vaccine baits were distributed at 75 baits/km² and 750-m flight-line spacing in the study area. Animal sampling occurred during 10-d intervals pre- and post-ORV during 2012–14 within eight study cells: four northern cells had a history of ORV with a different vaccine for 3 or more years prior and four southern cells were ORV naive. Baseline raccoon RVNA seroprevalence was 27.3% (n=1,079, 95% confidence interval [CI]: 24.8–30.1) before ORV in 2012. Raccoon RVNA seroprevalence averaged 68.5% (n=1,551, 95% CI: 66.2–70.8) post-ORV during the 3-yr study. The RVNA seroprevalence levels in this study were considered to be adequate for stopping raccoon RV transmission and supported and expanded the results from a West Virginia field trial, as well as earlier evaluations along the Canada–US border.