Efficacy of Ingelvac PRRS~R MLV against a heterologous PRRSV1-7-4 RFLP challenge

摘要

The swine industry continues to experience significant losses due to PRRS virus infections of sow farms and growing pigs.1 The use of Ingelvac PRRS~R vaccines can significantly reduce lung lesions following challenge with heterologous PRRSV isolates (86-94% ORF5 nucleotide similarity) in the three-week-old pig respiratory challenge model.2 In addition, it has been demonstrated that the implementation of a systematic methodology for PRRS control that utilizes modified-live vaccine for the control of wild type-PRRSV infections can mitigate the consequences of infection on health and performance.3 A It is necessary for modihed-live vaccines to be effective against heterologous challenge with current PRRSV field isolates. However, the efficacy of Ingelvac PRRS* MLV vaccine against a current virulent PRRSV RFLP 1-7-4 isolate has not been reported to date. The objective of this study was to evaluate the efficacy of Ingelvac PRRS~R MLV (BIVI-Boeh-ringer Ingelheim Vetmedica, Inc., St. Joseph, MO) and Fostera~R PRRS (Zoetis Inc., Kalamazoo, MI) in a three-week-old pig respiratory challenge model, using a heterologous PRRSV RFLP 1 -7-4 field isolate that was isolated from North Carolina in 2014.