Immunization of guinea-pigs and cattle with a reduced dose Clostridium chauvoei vaccine produced in a semi-synthetic medium.

A semi-synthetic culture medium and method are described for the production of a reduced dose Clostridium chauvoei vaccine. The vaccine gave excellent results in guinea-pigs, and 2 injections of 2.0 ml protected cattle against challenge with 2 M.L.D. of a virulent culture for at least 12 months. The suitability of C. chauvoei Strain OP64 as a vaccine strain was confirmed.