DNA Vaccination of the American Crow (Corvus brachyrhynchos) Provides Partial Protection Against Lethal Challenge with West Nile Virus

Authors:
  • PFPatricia E. Fox
    Patricia E. Fox
  • RBRichard A. Bowen
    Richard A. Bowen
  • NKNicholas Komar
    Nicholas Komar
  • GCGwong-Jen J. Chang
    Gwong-Jen J. Chang
  • TSTully J. Speaker
    Tully J. Speaker
  • MSMichael R. Stephens
    Michael R. Stephens
  • NNNicole Nemeth
    Nicole Nemeth
  • NPNicholas A. Panella
    Nicholas A. Panella
  • SLStanley A. Langevin
    Stanley A. Langevin
  • PGPaul Gordy
    Paul Gordy
  • MTMax Teehee
    Max Teehee
Publisher website
Google Scholar
Abstract
The New York 1999 strain of West Nile virus (WNV) is nearly 100% fatal in the American crow (Corvus brachyrhynchos). We evaluated four WNV vaccine formulations in American crows, including intramuscular (i.m.) DNA vaccine, i.m. DNA vaccine with adjuvant, orally administered microencapsulated DNA vaccine, and i.m. killed vaccine. Neutralizing antibodies developed in approximately 80% of crows that received the DNA vaccine i.m. (with or without adjuvant), and in 44% that received the killed vaccine. However, no crows that received the oral microencapsulated DNA vaccine or the placebo developed WNV antibodies. All crows were challenged 10 wk after initial vaccination. No unvaccinated crows survived challenge, and survival rates were 44% (i.m. DNA vaccine), 60% (i.m. DNA vaccine with adjuvant), 0% (oral microencapsulated DNA vaccine), and 11% (killed vaccine). Peak viremia titers in the birds that survived were significantly lower as compared to titers in birds that died. Parenteral administration of a WNV DNA vaccine was associated with reduced mortality but did not provide sterile immunity.