PRRSV (Porcine Reproductive and respiratory syndrome virus) is one of the most loss-causing agents in the global swine production. Partly due to reproductive losses plus birth of weak and viremic piglets from females viremic between day 70 of gestation and farrowing, partly due to the immunosuppressive action and respiratory disease in the infected naïve animal at any age. The virus is highly mutating and easily recombining between different strains into entirely new strains of potential high virulence. To control PRRSV on endemic farms internal biosecurity is key, which very often is an unfulfilled challenge. Finally, the single optimal PRRSV vaccine is not yet developed; MLV (modified live virus) PRRS vaccines have strong protection for “own” strain but poor cross-protection. INV (inactivated virus) PRRS vaccines have poor protection, when applied in naïve animals. However, Progressis produces a clinical and colostral protection when applied on previously naturally infected or MLV vaccinated animals. The optimal and safest PRRSV vaccination schedule is the Progressis Prime-Boost Concept, keeping breeding stock and new born PRRSV negative, with the potential of producing PRRSV negative piglets out of nurseries (app. 10 woa) depending on quality of biosecurity.