| Summary |
We describe in this work a specific, simple seologic method for the inspection and evaluation on the efficacy of vaccine against Actinobacillus pleuropneumoniae (AP) serotype I, II, were used for the preparation of CF, TA antigens, and all aharad good specificiy, with La antigen was the simplest of all.
In the laboratory-test, the 8-week-old piglets immunized with bacterins of the different AP serotypes were challenged with 3 ml of live AP bacteria at a concen-tration of I 09 CFU/ml by intranasal instillation. Only the group which had received a booster vaccination at 2-week intervals could survive the challenge, and the level of serum antibody before challenge (4 weeks after the first vaccination), determined by the CF, TA, and LA methods, were 4-8, 8-32, respectively. These revealed that pigs with antibody titer than I: 8 times have the ability to surve the challenge. In the field-test, The antibody titer in. booster group still it was higher than that of the pigs immunized with inactivated bacterin once. The highest antibody titers presnt at 8-week post-vaccination were 17.75-19.69, 28.84-33.12, and 20.39-28.84 (geometric mean), respectively for CF, TA, and LA metods.
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