F. Kovacs, G.Schagemann. International Symposium on Emerging and Re-Emerging Pig Diseases. 2003.
Porcine Reproductive and Respiratory Syndrome (PRRS) is a viral infectious disease of swine, which causes important economic losses. It was first described in the USA in 1987 and later in Canada and Europe in 1990. Clinical signs are mainly characterized by respiratory problems and reproductive failure causing abortions, mummified fetuses, and stillborn piglets. In addition, the surviving piglets are weak and show growth retardation.
The PRRS virus is single stranded and belongs to the Arterividae family, and the genus Arterivirus. The virus has high genetic and antigenic variability. European and American type isolates can be distinguished. Although, genetically they are clearly heterogenic, they are related in terms of serology and crossprotection.
Ingelvac® PRRS modified live vaccine, which contains an American type virus, is one available vaccine option worldwide. The heterogenic protective property of the vaccine is important for vaccine users. Cross-protection against virus isolate types, which are least genetically related to the American types, is of special interest. Once the immunogenicity of a vaccine strain is proven under heterologous challenge conditions, it can be recommended as a general tool in combating PRRS, despite the variability of the virus. The aim of the present paper is to demonstrate the efficacy of a single dose of Ingelvac“ PRRS modified live vaccine in protecting offspring from gilts infected with two heterologous virulent field isolates of European type virus.