Porcine reproductive and respiratory syndrome virus (PRRSV) is currently difficult to control with currently licensed vaccines. The inactivated vaccines do not induce protective immunity. They can only provide a boost immune response in animals when the strain in the vaccine is genetically equivalent to the circulating strain. The attenuated vaccines have given a very good protection in the nineties. The last decade has been the efficacy greatly deteriorated by genetic drift and antigenic of the circulating viruses. In the laboratory of the promoter of this project has recently developed an adaptable inactivated vaccine that recently the effect was demonstrated in the field. This new inactivated vaccine will be used to boost existing immunity in sows. With the present study will be developed an adjustable attenuated, and / or vector vaccines that can be used in naive animals (gilts and manure piglets). Wild-type virus will be attenuated by passages in two cell lines that were developed from the promoter in the laboratory: PK15 and CH0. By an ingenious system selection (reduced replication in macrophages but normal multiplication in cell lines), the attenuation will be followed in vitro. The mutants that grow well in cell cultures but not in macrophages will be further tested in vivo for their safety and effectiveness (induction of neutralizing antibodies and reducing viremia). In addition, the Bartha vaccine is to be used as a vector for expressing the extodomeinen of GP2, GP3 and GP4 of PRRSV which are under the regulation of certain proteins of the Bartha Virus (GC, GC, tegumeneiwit ...). The recombinant viruses Bartha will then be tested in vivo. The intramuscular vaccination will be compared with intranasal or peroral vaccination.