Submitted to: Porcine Reproductive and Respiratory Syndrome International Symposium
Publication Type: Proceedings
Publication Acceptance Date: 5/1/1995
Publication Date: N/A
Technical Abstract: Porcine reproductive and respiratory syndrome (PRRS) was first reported as epizootics of reproductive failure and a flu-like respiratory disease which had a high morbidity for all ages of swine. The etiology was discovered in 1991 and considerable progress has been made in elucidating the biology of the PRRS virus (PRRSV); however, the pathogenesis of the disease is still not completely understood. Anecdotal reports and field studies have indicated the immune response to PRRSV may range from an immunosuppressive state of unknown duration in piglets to a protective immunity in sows of at least a few months duration. Numerous controlled studies have been completed which have characterized the immune response of swine to a single PRRSV exposure; however, few reports are available on the consequences of a second exposure to virus, i.e., challenge of natural immunity and the possibility of one strain forming cross protection against other strains. The objective of this study was to test the ability of a North American strain (NADC-8) of PRRSV to induce protective immunity in pregnant gilts subsequently challenged with either the same or an antigenically distinct European strain (Lelystad) of PRRSV.