BOVI-SHIELD IBR Bovi-Shield IBR is a freeze-dried preparation of a modified live virus (MLV) strain of the IBR virus, plus a sterile diluent used to rehydrate the freeze-dried vaccine.Bovi-Shield IBR is for vaccination of healthy, nonpregnant cattle to prevent respiratory disease caused by infectious bovine rhinotracheitis (IBR) virus. A duration of immunity of at least 9 months has been demonstrated. When administered intramuscularly, Bovi-Shield IBR aids in preventing respiratory disease caused by IBR. Bovi-Shield IBR may be administered to calves nursing pregnant cows provided their dams were vaccinated, according to label directions, with any Bovi-Shield GOLD® FP® or PregGuard® GOLD FP vaccine within the past 12 months. To help ensure safety in pregnant cattle, heifers must receive at least 2 doses of any Bovi-Shield GOLD FP or PregGuard GOLD FP product with the second dose administered approximately 30 days prebreeding.