PMID- 29673363 OWN - NLM STAT- MEDLINE DCOM- 20180830 LR - 20181114 IS - 1746-6148 (Electronic) IS - 1746-6148 (Linking) VI - 14 IP - 1 DP - 2018 Apr 19 TI - Efficacy of live attenuated porcine reproductive and respiratory syndrome virus 2 strains to protect pigs from challenge with a heterologous Vietnamese PRRSV 2 field strain. PG - 133 LID - 10.1186/s12917-018-1451-y [doi] LID - 133 AB - BACKGROUND: Effective vaccines against porcine reproductive and respiratory syndrome virus (PRRSV), especially against highly pathogenic (HP) PRRSV are still missing. The objective of this study was to evaluate the protective efficacy of an experimental live attenuated PRRSV 2 vaccine, composed of two strains, against heterologous challenge with a Vietnamese HP PRRSV 2 field strain. For this reason, 20 PRRSV negative piglets were divided into two groups. The pigs of group 1 were vaccinated with the experimental vaccine, group 2 remained unvaccinated. All study piglets received an intranasal challenge of the HP PRRSV 2 on day 0 of the study (42 days after vaccination). Blood samples were taken on days 7 and 21 after vaccination and on several days after challenge. On day 28 after challenge, all piglets were euthanized and pathologically examined. RESULTS: On days 7 and 21 after vaccination, a PRRSV 2 viraemia was seen in all piglets of group 1 which remained detectable in seven piglets up to 42 days after vaccination. On day 3 after challenge, all piglets from both groups were positive in PRRSV 2 RT-qPCR. From day 7 onwards, viral load and number of PRRSV 2 positive pigs were lower in group 1 than in group 2. All pigs of group 1 seroconverted after PRRSV 2 vaccination. PRRSV antibodies were detected in serum of all study pigs from both groups from day 14 after challenge onwards. In group 2, moderate respiratory symptoms with occasional coughing were seen following the challenge with HP PRRSV 2. Pigs of group 1 remained clinically unaffected. Interstitial pneumonia was found in four piglets of group 1 and in all ten piglets of group 2. Histopathological findings were more severe in group 2. CONCLUSIONS: It was thus concluded that the used PRRSV 2 live experimental vaccine provided protection from clinical disease and marked reduction of histopathological findings and viral load in pigs challenged with a Vietnamese HP PRRSV 2 field strain. FAU - Sattler, Tatjana AU - Sattler T AUID- ORCID: 0000-0001-8946-6699 AD - Institute for Veterinary Disease Control, AGES, Robert-Koch-Gasse 17, 2340, Modling, Austria. tasat@vetmed.uni-leipzig.de. AD - Clinic for Ruminants and Swine, University of Leipzig, An den Tierkliniken 11, 04103, Leipzig, Germany. tasat@vetmed.uni-leipzig.de. FAU - Pikalo, Jutta AU - Pikalo J AD - Institute for Veterinary Disease Control, AGES, Robert-Koch-Gasse 17, 2340, Modling, Austria. FAU - Wodak, Eveline AU - Wodak E AD - Institute for Veterinary Disease Control, AGES, Robert-Koch-Gasse 17, 2340, Modling, Austria. FAU - Revilla-Fernandez, Sandra AU - Revilla-Fernandez S AD - Institute for Veterinary Disease Control, AGES, Robert-Koch-Gasse 17, 2340, Modling, Austria. FAU - Steinrigl, Adi AU - Steinrigl A AD - Institute for Veterinary Disease Control, AGES, Robert-Koch-Gasse 17, 2340, Modling, Austria. FAU - Bago, Zoltan AU - Bago Z AD - Institute for Veterinary Disease Control, AGES, Robert-Koch-Gasse 17, 2340, Modling, Austria. FAU - Entenfellner, Ferdinand AU - Entenfellner F AD - Veterinary Practice Entenfellner, Bonnleiten 8, 3073, Stossing, Austria. FAU - Claude, Jean-Baptiste AU - Claude JB AD - BioSellal, Batiment Accinov, 317 avenue Jean Jaures, 69007, Lyon, France. FAU - Pez, Floriane AU - Pez F AD - BioSellal, Batiment Accinov, 317 avenue Jean Jaures, 69007, Lyon, France. FAU - Francillette, Maela AU - Francillette M AD - BioSellal, Batiment Accinov, 317 avenue Jean Jaures, 69007, Lyon, France. FAU - Schmoll, Friedrich AU - Schmoll F AD - Institute for Veterinary Disease Control, AGES, Robert-Koch-Gasse 17, 2340, Modling, Austria. LA - eng PT - Journal Article DEP - 20180419 PL - England TA - BMC Vet Res JT - BMC veterinary research JID - 101249759 RN - 0 (RNA, Viral) RN - 0 (Vaccines, Attenuated) RN - 0 (Viral Vaccines) SB - IM MH - Animals MH - Enzyme-Linked Immunosorbent Assay/veterinary MH - Male MH - Porcine Reproductive and Respiratory Syndrome/immunology/*prevention & control/virology MH - Porcine respiratory and reproductive syndrome virus/genetics/*immunology MH - RNA, Viral/genetics MH - Real-Time Polymerase Chain Reaction/veterinary MH - Sequence Analysis, DNA/veterinary MH - Swine/immunology/virology MH - Treatment Outcome MH - Vaccines, Attenuated/therapeutic use MH - Viral Vaccines/immunology/*therapeutic use PMC - PMC5907707 OTO - NOTNLM OT - Efficacy OT - HP PRRSV 2 OT - Immune response OT - Vaccine OT - Viral replication COIS- ETHICS APPROVAL AND CONSENT TO PARTICIPATE: Housing, animal care and experimental protocol (notification number LF1-TVG-26/022-2014) were approved by the local ethics committee (Agency of the Government in Lower Austria, Department of Agrarian Law). The study piglets were bought by the Austrian Agency for Health and Food Safety for conduction of the study. Consent was given from the original owner of the pigs to conduct the study and take samples. COMPETING INTERESTS: The authors declare that they have no competing interest. PUBLISHER'S NOTE: Springer Nature remains neutral with regard to jurisdictional claims in published maps and institutional affiliations. EDAT- 2018/04/21 06:00 MHDA- 2018/08/31 06:00 PMCR- 2018/04/19 CRDT- 2018/04/21 06:00 PHST- 2017/06/06 00:00 [received] PHST- 2018/04/05 00:00 [accepted] PHST- 2018/04/21 06:00 [entrez] PHST- 2018/04/21 06:00 [pubmed] PHST- 2018/08/31 06:00 [medline] PHST- 2018/04/19 00:00 [pmc-release] AID - 10.1186/s12917-018-1451-y [pii] AID - 1451 [pii] AID - 10.1186/s12917-018-1451-y [doi] PST - epublish SO - BMC Vet Res. 2018 Apr 19;14(1):133. doi: 10.1186/s12917-018-1451-y.