Producers have used USDA licensed vaccines extensively to aid in the prevention of production losses, treatment costs, and death. Three studies were performed to demonstrate additional applications for USDA licensed products. In study 1, protection against an intranasal IBR virus challenge was seen 72-96 hours after parental vaccination; in study 2, vaccination with a type la BVDV vaccine provided protection against a severe type 2 challenge in weaned calves; and in study 3, fetal protection was shown after a heterologous BVDV challenge at 77 days of gestation. The results from these studies clearly demonstrated additional applications for three USDA licensed vaccines beyond label recommendations. (Abstract shortened by UMI.)