Submitted to: American Association of Avian Pathologists
Publication Type: Proceedings
Publication Acceptance Date: 6/30/2008
Publication Date: 7/21/2008
Citation: Tilley, B., Kapczynski, D.R., Gonder, E., Smith, C., Jackson, S. 2008. The role of vaccines and biosecurity in control of H3N2 swine influenza infection in turkey breeder flocks. In: Proceedings of the American Association of Avian Pathologists Annual Meeting, July 19-23, 2008, New Orleans, Lousiana. CDROM.
Interpretive Summary: Avian influenza (AI) is an important viral disease of commercial poultry worldwide. In U.S. turkey flocks, vaccination is used to control egg production losses associated with disease following infection by low pathogenic forms of AI. The objectives of this study were to extend the knowledge of vaccine induced protection by current AI vaccines in turkeys and determine if commercial vaccines protect against production losses from current AI field isolates. The results indicate that better protection from egg production losses is afforded to turkeys when the vaccine strain is more closely matched to the challenge virus. Overall these studies provide experimental data supporting the continued testing of vaccine isolates to provide increased protection of poultry against currently circulating field viruses.
Technical Abstract: Type A influenza virus infection in turkeys results in clinical signs ranging from asymptomatic to severe. Symptoms may include respiratory disease, drop in egg production, reduced hatchability, eggshell abnormalities, decreased feed efficiency, and increased mortality. In 2003, an H3N2 subtype of influenza triple reassortant containing human, swine, and avian gene segments, was isolated from turkey breeders in North Carolina housed in close proximity to a swine operation. The objective of this research was to determine if two different commercial oil emulsion inactivated AI H3 subtype vaccines would protect laying turkey hens from egg production losses following challenge with the 2003, H3N2 field virus isolate from North Carolina. Results indicate that following a natural route of challenge (eye drop / intranasal), both groups of vaccinated birds were protected from drops in egg production observed in sham-vaccinated hens. The results also indicate that the group of birds receiving either of the H3 vaccines had decreased number of unsettable eggs, and decreased virus isolations from cloacal swabs, compared to the sham-vaccinated birds. Overall these studies provide the first detailed protection studies of turkeys against an H3N2 triple reassortant AIV.