Clinical and immunologic responses of cattle to infectious bovine rhinotracheitis virus after infection by viral aerosol or intramuscular inoculation.

Aerosol or intramuscular exposure to infectious bovine rhinotracheitis virus elicited generally comparable levels of serum antibody in cattle, but not measurable nasal secretion antibody. Aerosol-exposed cattle developed signs of mild clinical disease, fever, and leukopenia and shed virus from their nasal passages. Cattle exposed by intra-muscular inoculation developed a brief febrile response and leukopenia but did not shed virus. After an aerosol challenge exposure, cattle in each group developed detectable nasal secretion antibodies, but no clinical signs of disease.