Vaccination of healthy cattle is recommended. Aseptically rehydrate the freeze-dried component with the sterile diluent provided, mix well and administer subcutaneously. In accordance with Beef Quality Assurance guidelines, this product should be administered subcutaneously in the neck region. Primary Vaccination: Administer a single 2-mL dose to healthy cattle. To avoid possible maternal antibody interference with active immunization, calves vaccinated before the age of 6 months should be revaccinated after 6 months of age or at weaning. Revaccination: Annual revaccination with a single dose is recommended. Good management practices support revaccination whenever subsequent stress or exposure is likely.