[Adaptation of attenuated strain of P. parainfluenzae-3 in cultured swine kidney cells and analysis of its immunogenicity].

Strain Mihailovgrad of P. parainfluenza-3 was successfully adapted to cell cultures of pig kidney at its 15th passage. Its testing for innocuity was carried out through the inoculation of test calves with high amounts of the pathogen. No pathologic, temperature, and anaphylactic reactions were established. This confirmed the harmless character of the attenuated strain. Comparative testing for immunogenicity was performed with 8-month-old calves. Full coincidence with the antibody response was obtained with strain Mihailovgrad as a vaccinal strain. The use of the adapted strain for the production of a vaccine is to be preferred as there is no possibility of contamination with other bovine viruses.