Safety and long-lasting immunity of the combined administration of a modified-live virus vaccine against and an inactivated vaccine against and in breeding pigs.

Background: In the field, vaccination schedules based on modified-live virus (MLV) vaccines administered twice in gilts and every three to four months in sows are commonly used to immunize breeding herds against (PRRSV). Breeding sows are repeatedly vaccinated against several other agents. Thus, the combined administration of vaccines for their simultaneous use can simplify such complex immunization schedules.