The range of neutralizing activity to bovine viral diarrhea (BVD) virus and viral protein specificity of antibodies induced by 3 inactivated vaccines were evaluated by use of samples of sera obtained from 13 cattle 14 days after vaccination. Viral neutralizing antibodies wee detected in all cattle to each of 10 noncytopathic and 10 cytopathic isolates of BVD virus. A viral-induced polypeptide (53,000 to 56,000 daltons) was detected by radioimmunoprecipitation with serum from all vaccinates. Other viral-induced polypeptides of 115,000, 80,000, 48,000, and 25,000 daltons were precipitated with sera from some vaccinates. Precipitation of those polypeptides was related to the vaccine used. When multiple viral polypeptides were precipitated, the 53,000- to 56,000-dalton polypeptide appeared immunodominant.