Further observations on the characteristics of a bovine parainfluenza-3 variant.

Calves were inoculated with a bovine para-influenza-3 variant to determine its pathogenicity and the stability of its cytopathic feature and its inability to agglutinate chicken erythrocytes. The inoculated calves and one contact animal developed an immune response without significant clinical illness. The clinical response in calves was similar to that induced by the parent virus strain. The variant was shown to retain its characteristic cytopathic effect for Madin Darby bovine kidney cells and its property of hemagglutination following one passage in the natural host.