Immunoglobulins and their relative neutralizing efficiency in cattle immunized with infectious bovine rhinotracheitis--parainfluenza-3 (IBR-PI-3) virus vaccine.

The localization of anti-IBR and anti-PI-3 activity in the serum and nasal secretory immunoglobulins following intranasal immunization of cattle with a mixed vaccine (IBR-PI-3, MLV, TCO) was studied and was found to reside in the nasal secretory IgA, serum IgM and IgG fractions. The computation of their relative virus neutralizing efficiencies from kinetic data revealed their order of neutralizing efficiencies to be IgM greater than IgA greather than IgG.