Submitted to: Swine Disease Conference Proceedings
Publication Type: Proceedings
Publication Acceptance Date: 11/10/1995
Publication Date: N/A
Technical Abstract: Porcine reproductive and respiratory syndrome (PRRS) is considered to be one of the most economically important viral diseases of pigs that is currently faced by the United States swine industry. Differences in the seriousness of clinical signs associated with naturally occurring epizootics of PRRS suggest the existence of different virulence (i.e. disease producing) strains of the PRRS virus. The study reported here confirms this idea in that when susceptible pregnant gilts were exposed during gestation to selected strains of PRRS virus the consequences depended on the strain to which the gilts had been exposed, and varied from death of entire litters in utero to birth of clinically normal, apparently healthy piglets. These results emphasize that strain selection is likely to be an important consideration in the development of attenuated vaccines for control of the disease.