Immunogenic composition of killed
The present invention pertains to a composition containing an immunogenic cell preparation of killed Leptospira bacteria in a citric acid solution. It also pertains to a vaccine to protect an animal against an infection with Leptospira bacteria, wherein the vaccine comprises this composition, and to the use of citric acid to stabilize an immunogenic preparation of killed Leptospira bacteria in a liquid carrier, by dissolving the citric acid in the carrier.
1. composition containing an immunogenic cell preparation of killed Leptospira bacteria in a citric acid solution.
2. The composition of claim 1 , wherein the solution comprises 20 mmols of citric acid per liter.
3. The composition of claim 2 , wherein the solution is buffered at a pH between 5 and 6.
4. The composition of claim 1 , wherein the solution is buffered at a pH between 5 and 6.
5. The composition of claim 2 , wherein the Leptospira bacteria are chosen from Leptospira interrogans serogroup Canicola serovar Portland-Vere, Leptospira interrogans serogroup Australis serovar Bratislava, Leptospira interrogans serogroup Icterohaemorrhagiae serovar Copenhageni and Leptospira kirschneri serogroup Grippotyphosa serovar Dadas.
6. The composition of claim 1 , wherein the Leptospira bacteria are chosen from Leptospira interrogans serogroup Canicola serovar Portland-Vere, Leptospira interrogans serogroup Australis serovar Bratislava, Leptospira interrogans serogroup Icterohaemorrhagiae serovar Copenhageni and Leptospira kirschneri serogroup Grippotyphosa serovar Dadas.
7. The composition of claim 6 , wherein the Leptospira bacteria are Leptosira interrogans serogroup Australis serovar Bratislava.
8. The composition of composition of claim 5 , wherein the Leptospira bacteria are Leptosira interrogans serogroup Australis serovar Bratislava.
9. A vaccine to protect an animal against an infection with Leptospira bacteria comprising the composition of claim 8 .
10. A vaccine to protect an animal against an infection with Leptospira bacteria comprising the composition of claim 7 .
11. A vaccine to protect an animal against an infection with Leptospira bacteria comprising the composition of claim 6 .
12. A vaccine to protect an animal against an infection with Leptospira bacteria comprising the composition of claim 5 .
13. A vaccine to protect an animal against an infection with Leptospira bacteria comprising the composition of claim 4 .
14. A vaccine to protect an animal against an infection with Leptospira bacteria comprising the composition of claim 3 .
15. A vaccine to protect an animal against an infection with Leptospira bacteria comprising the composition of claim 2 .
16. A vaccine to protect an animal against an infection with Leptospira bacteria comprising the composition of claim 1 .
17. A method of stabilizing an immunogenic preparation of killed Leptospira bacteria in a liquid carrier that comprises dissolving the citric acid in the liquid carrier.
18. The method of claim 17 wherein the preparation retains at least 25% of its antigenic mass during a 3 month storage at a temperature above 18° C.