|Becerra, V - CVB, APHIS, USDA|
|Eernisse, K - CVB, APHIS, USDA|
|Gatewood, D - CVB, APHIS, USDA|
Submitted to: American Association of Bovine Practitioners Proceedings
Publication Type: Proceedings
Publication Acceptance Date: September 22, 2005
Publication Date: September 22, 2005
Citation: Ridpath, J.F., Neill, J.D., Becerra, V., Eernisse, K., Gatewood, D. 2005. Reproducible challenge model for BVDV vaccine efficacy studies. In: Proceedings of the 38th Annual Convention of the American Association of Bovine Practitioners, September 22-24, 2005, Salt Lake City, Utah. p. 290-291. Technical Abstract: Accurate determination of vaccine efficacy is dependent upon the use of challenge viruses that reproducibly cause notable clinical disease. Historically the challenge virus, made available by the Center for Veterinary Biologics, for vaccine efficacy studies and licensing is the BVDV type 1 strain NY-1. Clinical signs following infection with this strain are minimal and consist of a small rise in temperature usually lasting less than 48 hours and a 20% or less transient drop in circulating lymphocytes. Because the clinical signs following infection are so mild, it is difficult to assess disease protection after vaccination when this virus is used as the challenge. In this study we provide documentation of the clinical presentation following infection with a highly virulent type 2 BVDV. This virus, 1373, was isolated following an outbreak of severe acute BVDV in Ontario, Canada in 1993. Acute uncomplicated infection with this virus reproducibly results in clinically severe disease as described below.