Porcine reproductive and respiratory syndrome of attenuated life process for preparing the same vaccine for the protection of pigs against infection by the virus and process for preparing the vaccine

摘要

The present invention is concerned with European strains of the Porcine Reproductive Respiratory Syndrome (PRRS) virus, having as a unique feature that they are non-infectious to macrophages, and to methods for the production of such strains. The invention also provides vaccines for the protection of pigs against PRRS, based on these strains, as well as methods for the production of such vaccines.