[Experiments to obtain and test vaccines against enzootic pneumonia in swine]

Five-day-old PPLO broth cultures of two Mycoplasma hyorhinis strains were used to obtain an inactivated vaccine consisting of 75 parts culture, 25 parts aluminum hydroxyde and 0.1 per cent formalin, and a live vaccine of 75 parts culture and 25 parts aluminum hydroxyde. The inactivated vaccine was tested on a total of 320 pregnant pigs and the live one--on 3,150 pigs, aged two-three months on a farm with a record of M. hyorhinis infection resulting in an enzootic pneumonia. In those of the pigs that were born by the vaccinated sows and were later on vaccinated themselves the percent of enzootic penumonia morbidity was reduced to 50.