The Development and Evaluation of a New Inactivated Vaccine against Mycoplasma capricolum subsp. capricolum.

Mycoplasma capricolum subsp. capricolum (Mcc) and Mycoplasma capricolum subsp. capripneumoniae (Mccp) are pathogens that affect large and small ruminants. Indeed, Mcc affects both sheep and goats, causing contagious agalactia (CA). Mccp affects only goats, causing contagious caprine pleuropneumonia (CCPP). CA and CCPP are mainly controlled using inactivated Mcc and Mccp vaccines. However, producing the vaccine with the Mccp strain is complex, fastidious, and costly due to the slow growth of the bacterium. In this study, we present new oil-adjuvanted and inactivated Mcc and Mccp vaccines for sheep and goats against CA and CCPP. The vaccines were evaluated for safety and efficacy using experimental infection. A serological response was observed one week after of the first vaccination of sheep and goats with Mcc and goats with Mccp. The vaccinated animals were subsequently challenged with the virulent Mcc MOR20 strain. The Mcc vaccine was demonstrated to provide robust protection when the animals were challenged with Mcc MOR20. Cross-protection against the Mcc MOR20 challenge was also obtained with the Mccp vaccine. This finding revealed, for the first time, the safety and efficacy of an inactivated Mcc vaccine against contagious agalactia and cross-protection between Mcc and Mccp strains.