Immunogenic composition of killed leptospira bacteria
The present invention pertains to a composition containing an immunogenic cell preparation of killed Leptospira bacteria in an ethylenediaminetetraacetic acid solution. The invention also pertains to a vaccine to protect an animal against an infection with leptospira bacteria, wherein the vaccine comprises this composition. Also, the invention pertains to the use of ethylenediaminetetraacetic acid to stabilise an immunogenic preparation of killed Leptospira bacteria in a liquid carrier, by dissolving the ethylenediaminetetraacetic acid in the carrier.
1. A composition containing an immunogenic cell preparation of killed Leptospira bacteria in an ethylenediaminetetraacetic acid solution; wherein the solution comprises 5 to 50 mmols of ethylenediaminetetraacetic acid per liter; wherein the Leptospira bacteria are selected from the group consisting of Leptospira interrogans serogroup Canicola serovar Portland-Vere, Leptospira interrogans serogroup Icterohaemorrhagiae serovar Copenhageni, and Leptospira kirschneri serogroup Grippotyphosa serovar Dadas.
2. The composition of claim 1 , wherein the solution comprises 20 mmols of ethylenediaminetetraacetic acid per liter.
3. The composition of claim 2 , wherein the solution contains dibasic sodium phosphate.
4. The composition of claim 1 , wherein the solution contains dibasic sodium phosphate.
5. The composition of claim 1 , wherein the Leptospira bacteria are Leptospira interrogans serogroup Canicola serovar Portland-Ver.
6. A vaccine to protect an animal against an infection with leptospira bacteria, wherein the vaccine comprises the composition of claim 5 .
7. A vaccine to protect an animal against an infection with leptospira bacteria, wherein the vaccine comprises a composition of claim 2 .
8. A vaccine to protect an animal against an infection with leptospira bacteria, wherein the vaccine comprises the composition of claim 4 .
9. A vaccine to protect an animal against an infection with leptospira bacteria, wherein the vaccine comprises the composition of claim 3 .
10. A vaccine to protect an animal against an infection with leptospira bacteria, wherein the vaccine comprises the composition of claim 1 .
11. A method of stabilizing an immunogenic preparation of killed Leptospira bacteria in a liquid carrier, comprising dissolving ethylenediamine-tetraacetic acid in the liquid carrier; wherein the solution comprises 5 to 50 mmols of ethylenediaminetetraacetic acid per liter; wherein the Leptospira bacteria are selected from the group consisting of Leptospira interrogans serogroup Canicola serovar Portland-Vere, Leptospira interrogans serogroup Icterohaemorrhagiae serovar Copenhageni, and Leptospira kirschneri serogroup Grippotyphosa serovar Dadas.
12. The method of claim 11 wherein the preparation retains at least 25% of its antigenic mass during a 3 month storage at a temperature above 18° C.
13. The method of claim 11 wherein the preparation retains at least 25% of its antigenic mass during a 3 month storage at a temperature between 18° C. and 37° C.
14. The method of claim 11 wherein the preparation retains at least 25% of its antigenic mass during a 3 month storage at 37° C.