An efficient vaccine would be a useful weapon in the fight against dysentery in pigs. Our research group used an avirulent strain of B. hyodysenteriae in an in vivo vaccination trial. The use of this strain as a weakened live vaccine seems promising. In a first phase, further research would mainly focus on confirming the efficacy and safety of the vaccine strain in a large vaccination experiment. The vaccine strain would be tested in a model that is closer to the business situation. Another important point is the development of a diagnostic test that can distinguish infected animals from vaccinated animals (DIVA). In a second phase, the development of humoral and cellular immunity in vaccinated pigs will be investigated and the vaccine strain will be further characterized. In this phase an industrial partner will optimize the production of the vaccine on a large scale and the storage possibilities of the vaccine.