|Sa E Silva, Mariana|
Submitted to: Vaccine
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 12/10/2012
Publication Date: 1/3/2013
Publication URL: http://handle.nal.usda.gov/10113/57536
Citation: Sa E Silva, M., Ellis, A., Karaca, K., Minke, J., Nordgren, R., Wu, S., Swayne, D.E. 2013. Domestic goose as a model for West Nile virus vaccine efficacy. Vaccine. 31(7):1045-1050. Interpretive Summary: West Nile virus (WNV) is an important pathogen for several mammals, including humans, and also several bird species. Among the susceptible birds, geese are the most susceptible to acquired and spread infection. The aim of this study is to report a vaccine efficacy model for WNV using geese, evaluating several protection parameters. The birds were divided in groups and vaccinated with different vaccine formulations, followed by a challenge with the WNV. The fowlpox recombinant vaccine provides the best overall protection compared with the control group not vaccinated and only challenged. The data reported in this study indicates that geese can be used as a model for vaccine protection studies against WNV.
Technical Abstract: West Nile virus (WNV) is an emergent pathogen in the Americas, first reported in New York during 1999, and has since spread across the United States (USA), Central and South America causing neurological disease in humans, horses and some bird species, including domestic geese. No WNV vaccines are licensed in the USA for use in geese. This study reports the development of a domestic goose vaccine efficacy model, based on utilizing multiple parameters to determine protection. To test the model, 47 geese were divided in seven groups: five different vaccine groups and two sham groups (challenged and unchallenged). Based on the broad range of result for individual metrics between the Challenged-Sham and Unchallenged-Sham groups, the best parameters to measure protection were morbidity, Clinical Pathogenicity Index (CPI), plasma virus positive rates on 1-4 days post-inoculation and titers, and brain histological lesion rates and severity scores. Compared to the Challenged-Sham group, the fowlpox virus vectored vaccine (vFP2000) with inserts of WNV membrane protein (prM) and envelope (E) proteins provided the best protection with significant differences in all six metrics, followed by the two canarypox virus vectored vaccines with inserts of WNV prM and E proteins (vCP2017 and vCP2018) with four metrics of protection, WNV E protein with two metrics of protection and Oil-emulsion whole WNV with one metric of protection. This data indicate domestic geese can be used in an efficacy model for vaccine protection studies, using clinical, plasma virological and brain histopathological parameters to evaluate protection against WNV challenge.