title: One-time intradermal DNA vaccination in ear pinnae one year prior to infection protects dogs against rabies virus.
abstract: Rabid dog exposures result in > 99% of human rabies deaths worldwide. Ninety-eight percent of these cases occur in developing countries. Thus, the best protection against human rabies would be prevention through adequate vaccination of the reservoir population. The difficulty in re-locating ownerless, freely roaming dogs for booster vaccinations, in addition to poor coverage with inadequate vaccines, suggests that a potentially inexpensive vaccine that elicits long-term protection after a single-dose could improve control of canine rabies in developing countries. One solution could be a DNA vaccine. We have previously determined that dogs vaccinated intradermally (i.d.) in ear pinnae with a rabies DNA vaccine expressing a rabies virus glycoprotein (G) produce high levels of neutralizing antibody that persist for at least 6 months. In the present study, we determined whether a one-time i.d. rabies DNA vaccination into ear pinnae 1 year before viral challenge would protect dogs against rabies virus. The dogs did not receive a booster vaccination. All dogs (100%) vaccinated i.d. in each ear pinna with 50 microg of rabies DNA vaccine, or intramuscular (i.m.) with a commercial canine rabies vaccine survived a lethal dose of rabies virus. In contrast, 100% of dogs vaccinated i.m. with 100 microg of rabies DNA developed rabies, as did 100% of negative control dogs that were vaccinated i.d. in each ear pinna or i.m. with DNA that did not express the rabies virus G. The data suggest that a one-time i.d. rabies DNA vaccination into ear pinnae offers a new approach to facilitate control of endemic canine rabies in developing countries.
authors.affiliation: Laboratory of Persistent Viral Diseases, Rocky Mountain Laboratories, National Institute of Allergy and Infectious Diseases, 903 South Fourth Street, Hamilton, MT 59840, USA. dlodmell@nih.gov
authors.forename: Donald L
authors.initials: DL
authors.lastname: Lodmell
authors.forename: Larry C
authors.initials: LC
authors.lastname: Ewalt
authors.forename: Michael J
authors.initials: MJ
authors.lastname: Parnell
authors.forename: Charles E
authors.initials: CE
authors.lastname: Rupprecht
authors.forename: Cathleen A
authors.initials: CA
authors.lastname: Hanlon
mesh_terms: D000818:Animals; D000914:Antibodies, Viral / Q000096:biosynthesis* / Q000097:blood; D004285:Dogs; D004431:Ear, External; D007117:Immunization, Secondary; D007271:Injections, Intradermal; D011818:Rabies / Q000276:immunology / Q000517:prevention & control* / Q000662:veterinary*; D011819:Rabies Vaccines / Q000008:administration & dosage* / Q000276:immunology; D011820:Rabies virus / Q000235:genetics; D014611:Vaccination; D019444:Vaccines, DNA / Q000008:administration & dosage / Q000276:immunology
chemical_list: D000914:Antibodies, Viral; D011819:Rabies Vaccines; D019444:Vaccines, DNA