Use in Cattle of Formalin-Killed Polyvalent Vaccine with Adjuvant Against Infectious Bovine Rhinotracheitis, Bovine Viral Diarrhea, and Parainfluenza-3 Viruses

SUMMARY A formalin-inactivated polyvalent vaccine was prepared with infectious bovine rhinotracheitis (ibr), bovine viral diarrhea (bvd), and parainfluenza-3 (pi-3) viruses. This vaccine and a similar preparation combined with sodium alginate as adjuvant, as well as monovalent vaccines prepared with each of the 3 viruses with the same adjuvant, were used for immunization of cattle. The neutralization index (ni) of the circulating antibodies, produced in response to 1 inoculation of the polyvalent vaccine without the adjuvant, to ibr, bvd, and pi-3 were 2.5, 1.1, and 3.2, respectively. The ni to 2 inoculations of the same vaccine were 2.8, 2.9, and 3.5. However, after 1 and 2 inoculations of this vaccine mixed with adjuvant, the ni were observed to be significantly higher. The ni of serums of cattle inoculated twice (38 days apart) with monovalent adjuvant-containing vaccines were similar to those obtained in cattle given 2 inoculations of the polyvalent adjuvant-containing preparation. Circulating antibodies persisted in the cattle throughout the 120-day experiment.