[Investigation about development of alternative efficacy verifications of swine erysipelas vaccines]

Vaccination is the most effective prophylaxis against swine erysipelas. Vaccines are usually tested for efficacy by a challenge of vaccinated and untreated pigs. Up to now the efforts to replace the infection test by a serological method have been limited to the potency test in laboratory animals. Here we provide evidence that the measurement of antibodies by an enzyme-linked immunosorbent assay (ELISA) after vaccination and challenge is also possible in the target species. Pig sera were tested for titre development after a single and repeated vaccination in clinical trials. The efficacy of the vaccines was confirmed by a challenge, which demonstrated that all immunized pigs survived with no signs of disease whereas all control animals became severely ill. The ELISA was also used to measure erysipelas antibodies after immunization of pigs with several vaccines in a field trial. The ELISA may be a suitable alternative to replace the challenge methods currently used for testing of erysipelas vaccines.