Vaccination trials against Mycoplasma mycoides subsp. mycoides (large-colony-type) infection in goats

Vaccination trials against Mycoplasma mycoides subsp. mycoides in suckling and weaned kids are described. A formalin-killed vaccine with adjuvant was used. Challenge to the vaccinated suckling kids was by ingestion of dam's infected milk and by subcutaneous inoculation of 10(6) organisms, and to the vaccinated weaned kids, by subcutaneous inoculation alone. The weaned 6-week-old kids were vaccinated, given a booster 3 weeks later and challenged 1 month after that. Serological monitoring was by enzyme-linked-immunosorbent assay (ELISA). The six control kids remained serologically negative and after challenge were pyrexic and mycoplasmaemic. All died or were killed in extremis, with a characteristic cellulitis at the site of inoculation, arthritis and swollen spleen. In contrast, the vaccinated kids remained healthy. There was a modest antibody response to the initial vaccination and a further steep rise after the booster. After challenge the organism was recovered only from the lymph nodes proximal to the site of challenge in some animals, and from the liver and kidney in two animals. All the vaccinated suckling kids were unaffected by ingestion of their dam's infected milk. The kids that received only one vaccine inoculation on the day of birth, and one control kid, succumbed to subcutaneous challenge, whereas the kids that were given a booster, except for one, remained healthy.