Patent ID: 8491915

Claim:
An immunogenic composition which comprises: a) an emulsion comprising an oil and one or more emulsifiers; and b) a heat treated bacterin comprising a suspension of killed Leptospira bacteria, wherein the killed Leptospira bacteria are one to five Leptospira species selected from the group consisting of Leptospira canicola, Leptospira grippotyposa, Leptospira hardjo, Leptospira icterohaemorrhagiae , and Leptospira Pomona , wherein said bacterin has a lipase activity of 50% or less than the lipase activity of the bacterin before heat treatment, and further wherein said bacterin has acceptable antigenic activity; wherein said composition has increased stability when compared with a composition comprising a non-heat treated bacterin and: i) wherein the lipase activity of said bacterin is above zero; or ii) said bacterin is heated to a temperature of 55 to 65° C. for 5 to 8 hours, or iii) said bacterin is heated to a temperature of 65 to 70° C. for 5 to 8 hours, or iv) said bacterin is heated to a temperature of 65 to 70° C. for 1 hour, or v) said bacterin is heated to a temperature of 60 to 70° C. for 9 to 10 hours.