| 摘要 |
<p>A living virus vaccine for the immunisation of cattle against parainfluenza-3-virus infection is prepared by attenuating a parainfluenza-3-virus by growth cycles in epithelial cell cultures of calves' kidneys, cultivating the 91st to 93rd growth cycles with a serum-free medium in epithelial cell cultures of calves' kidneys, and collecting the attenuated virus-containing medium after 2 to 3 days incubation. The latter medium can be used either as a liquid inoculum or lyophilised. The liquid or lyophilised inoculum may be administered parenterally or intranasally.</p> |
