Leptospiral vaccines in dogs: immunogenicity of whole cell and outer envelope vaccines prepared in protein-free medium.

The immunogenicity of leptospires cultivated in modified bovine albumin-polysorbate 80 medium and those cultivated in protein-free medium were quantitatively evaluated in the dog. Vaccine preparations, whole cell or outer envelope, prevented leptospiremia; however, kidney culture data revealed that 1 of 4 dogs vaccinated with 0.1 to 1 mg of whole cell prepared from leptospires cultivated in the modified bovine albumin-polysorbate 80 medium was positive for Leptospira, whereas dogs vaccinated with whole cells prepared in protein-free medium were not. Dogs vaccinated with greater than or equal to 0.5 mg of outer envelope were refractory to infection after challenge exposure.