Vaccination of Captive Nene (Brenta sandvicensis) against West Nile Virus Using a Protein-based Vaccine (WN-80E)

Although West Nile Virus (WNV) has not been reported in Hawan, eventual introduction appears unavoidable with potential adverse effects on avian species. Nene (Branta sandvicensis) are endemic endangered Hawaiian geese that are susceptible to WNV. We demonstrate that a vaccine developed against WNV for humans (WN-80E) is also highly immunogenic in Nene and does not produce adverse biologic effects. Six captive, nonbreeding Nene were immunized with two 10-mu g doses (4 wk apart) of the WN-80E recombinant protein adjuvanted with Montanide ISA720. Two Nene were similarly injected with mock preparation as controls. Blood samples were collected before the first dose, then 2 wk and 6 mo after the second dose. WNV-specific antibody titers were determined by an endpoint enzyme-linked immunosorbent assay. An unpaired t-test demonstrated significantly higher geometric mean titers for immunized vs. control groups 2 wk after dose 2(4,129 and 100, respectively, P=0.010) and 6 mo after dose 2 (246. and 63, respectively, P=0.002). Daily observations revealed no swelling at the site of injection and no serious adverse biological effects from the immunization. The vaccine containing the WN-80E and Montanide ISA720 adjuvant appears to be safe and immunogenic in Nene. This protein-based WNV vaccine may be safer for use in Hawai'i than killed virus and live chimeric or recombinant canarypox-vectored vaccines because it cannot cause disease.