| Summary |
Mice and pigs were used to test the safety and efficacy of mono-and poly-valent inactivated vaccines and mono-valent attenuated vaccine of erysipelas. The results showed no side reactions on either experimental animals, even when 10 times doses for pigs were used in mice. When the mice were immunized, subcutaneously, with 1.4 X 104 CFU of attenuated vaccine they resisted to the challenge of 100 MLD of a virulent Erysipelothrix rhusiopathiae (Er). Although the inactivated vaccine is very safe, a vaccination dose of 3 X 101° CFU was required for the protection from the 100 MLD challenge. On the other hand, the growth agglutination (GA) titers of four pigs were 1 : 32 when the sera were collected at two weeks after vaccination using attenuated vaccine. In addition, no distinct changes in the GA titers were found at two weeks after challenge ( 4 weeks after vaccination ). However, the GA titers were 1 : 8 for other 6 pigs when the sera were tested at 2 weeks after vaccination with inactivated vaccine. The titers increased to 1 : 128 to 1 : 512 when the sera were tested at two weeks after challenge. These increased titers were apparently due to the exposure of pigs to challenge with Er. The results indicated that the efficacy of the attenuated vaccine is better than that of the inactivated bacterin.
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