|Gauger, Phillip -|
|Kehrli Jr, Marcus|
Submitted to: American College of Veterinary Pathologists Meeting
Publication Type: Abstract Only
Publication Acceptance Date: July 15, 2012
Publication Date: December 1, 2012
Citation: Henningson, J.N., Braucher, D.R., Vincent, A.L., Loving, C.L., Kitikoon, P., Gauger, P.C., Kehrli, M.E. 2012. Adenovirus vectored vaccines against influenza A virus do not result in vaccine associated enhanced respiratory disease following heterologous challenge in contrast to whole inactivated virus vaccine. American College of Veterinary Pathologists Meeting 63rd Annual Meeting. Paper No. E-2. Technical Abstract: Heterologous influenza A virus (IAV) challenge following vaccination with an intramuscular (IM) whole inactivated vaccine (WIV) can result in vaccine-associated enhanced respiratory disease (VAERD). The objective of this study was to use an adenovirus (Ad5) vector vaccine platform that expressed IAV hemagglutinin (HA) or nucleoprotein (NP) to determine if the Ad5-vectored vaccine platform would result in VAERD as has been seen with WIV vaccine. Weaned commercial pigs were separated into 7 groups (n=8) and received 2 doses three weeks apart of either IM Ad5-HA, IM Ad5-NP, IM Ad5-HA + NP (2 groups), IM WIV vaccine (VAERD positive control group), IM Ad5-empty vector or intranasal (IN) Ad5-HA + NP. Three weeks post boost vaccination six groups of pigs were challenged with heterologous 106 TCID50 /mL H1N1pdm09 (A/California/04/09 (CA/09)). The VAERD control group had the most severe lesions, characterized by multifocal purple consolidation affecting an average of 17.7% of the total lung area. Groups vaccinated with IM Ad5-HA, IM Ad5-NP, IM Ad5-HA+NP, IN Ad5-HA+NPand IM Ad5-empty had 3.5%, 8.9%, 5.8%, 4.7%, and 6.0% lung consolidation, respectively. Histopathology lesions followed a similar pattern and were most severe in the WIV VAERD control group. The Ad5 vectored HA, whether given IN or given IM alone or in combination with Ad5-NP protected against lung lesions and did not contribute to VAERD. In conclusion, pigs vaccinated with Ad5 vaccines had significantly reduced lung lesions as compared to the VAERD pigs. These results illustrate replication deficient Ad5-vectored vaccines with either IAV HA or NP proteins were not associated with VAERD.