(Pfizer Animal Health) Fostera PRRS is a porcine reproductive and respiratory syndrome vaccine. For vaccination of healthy, susceptible swine in PRRS virus-positive herds or seronegative pigs deemed at risk to exposure to PRRS, or in preventing disease associated with Porcine Reproductive and Respiratory Syndrome Virus. Aseptically rehydrate the freeze-dried vaccine with the sterile diluent. Shake well and administer 2 ml IM to pigs 3 weeks of age or older. Do not vaccinate pregnant swine or boars of breeding age. Modified live. Requires mixing.