| Summary |
In order to develope a live-virus vaccine against Pseudorabies for Swine use, the isolates of N, and T, strain have been passaged in various cell line cultures for a long period, and purified by plaque forming method in every other 20 subpassages. After the pathogenicity test of these attenuated isolates in rabbits have been finished, the results of the test revealed the virulence of the isolates after 120 subpassages in Bovine Kidney Cell in Rabbits were weakener than those of the isolates after 160 subpassages in Rabbit Kidney Cell (RK-13), and 120 subpassages in Embryonic Swine Kidney.
The 4-week old piglets were vaccinated by the attenuated isolate of N, strain after 120 subpassages in Bovine Kidney (N,-BK-120) with 1/10 dose (1 dose: 10 TC ID50/ml) (l)*, 1/5 dose (1), 1 dose (2), 5 dose (1), and 10 dose (1). And challenge at 8th day after being vaccinated by the virulent virus of Pseudorabies of Aujeszky's strain. And all the vaccinated piglets have survived from being challenged but control piglet.
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