- 1 minute, 18 seconds
- Expertise article
- Caroline Bonckaert, Chris-an KraU, Guy Cluydts, Hans Nauwynck
Introduction
Porcine Reproduc-ve and Respiratory Syndrome Virus (PRRSV) can be divided in 3 subtypes. Subtype 1 strains in Belgium cause reproductive disorders in breeders and is involved in porcine respiratory disease complex in young pigs. In 2013, a pathogenic strain was isolated on a Belgian farm where piglets suffered from respiratory disorders. Thestrain was called Flanders’13 (Frydas et al., 2015). The degree of clinical and virological protec-on was assessed in pigs vaccinated with the new commercially available PRRSV vaccine Ingelvac PRRSFLEX EU® (Boehringer Ingelheim) and challenged six weeks later with the Flanders ‘13 PRRSV strain.
Material and methods
Twelve 4-weeks-old piglets from a PRRSV-nega-ve farm were divided in 2 groups. Group Vac was vaccinated intramuscularly with Ingelvac PRRSFLEX EU® and group Unvac was leU unvaccinated. All piglets were challenged intranasally with PRRSV strain Flanders ‘13 (2 ml, 105 TCID50/dose) six weeks aUer vaccina-on and clinical, virological and serological parameters were followed in time.
Results
All vaccinated pigs seroconverted within two weeks post vaccina-on, whereas the control animals remained negative until challenge. Fever and other clinical signs were excep-onally observed in both groups upon challenge. A partial virological protection was observed in vaccinated piglets: viral load and nasal shedding was significantly reduced in titer (large figure) at 3, 7 (shedding), 10 and 14 dpc (viremia), dura-on (2.5 and 6.16 days, respectively) and AUC (small figure) compared to the unvaccinated animals.
Conclusion
A partial protec-on was observed upon challenge with subtype 1 PRRSV strain Flanders ‘13 in pigs vaccinated with the new live aaenuated vaccine Ingelvac PRRSFLEX EU®. Viremia and nasal shedding of PRRSV Flanders ‘13 was significantly reduced in vaccinated animals.