This product has been shown to be effective for the vaccination of healthy swine 3 weeks of age or older against respiratory disease caused by Porcine Reproductive and Respiratory Syndrome (PRRS) virus and female breeding age swine against reproductive disease caused by PRRS virus. For sows and gilts, inject a single 1 mL dose intramuscularly (IM) 8 weeks prior to breeding, and for piglets, inject a single 1 mL dose IM at 3 weeks of age or older (see complete label instructions). Freeze-dried MLV vaccine with diluent.