Effects of attenuated vaccine protocols against Salmonella Typhimurium on Salmonella serology in subclinically infected pig herds

Publication date: Available online 23 May 2019Source: The Veterinary JournalAuthor(s): L. Peeters, J. Dewulf, F. Boyen, C. Brossé, T. Vandersmissen, G. Rasschaert, M. Heyndrickx, M. Cargnel, F. Pasmans, D. MaesAbstractVaccination of pigs against Salmonella Typhimurium (S. Typhimurium) can be effective for the control of Salmonella infections at the farm level and reduce the risk of Salmonella contamination in the food chain. However, vaccination may interfere with herd serological status in serology-based Salmonella monitoring programs. The present study investigated the effects of an attenuated S. Typhimurium vaccine (Salmoporc, IDT Biologika) on Salmonella serology in sows, neonatal piglets and slaughter pigs from three subclinically infected herds. Within each herd, five different vaccination protocols were tested as follows: group 1, vaccination of sows; group 2, vaccination of sows and piglets; group 3, vaccination of sows and fattening pigs; group 4, vaccination of piglets; and group 5 vaccination of fattening pigs. Each group was compared to a non-vaccinated control group (group 6). Sera were analyzed by ELISA (HerdChek Swine Salmonella, IDEXX Laboratories) and sample-to-positive (S/P) ratios were calculated.At day 3 after farrowing, but not before vaccination, S/P ratios in vaccinated sows (mean: 2.21) were significantly higher than S/P ratios in non-vaccinated sows (mean: 0.87, P < 0.001). S/P ratios in 3-day old piglets from vaccinated sows (mean: 2.46) wer...
Source: The Veterinary Journal - Category: Veterinary Research Source Type: research