Heat treated bacterins, and emulsion vaccines prepared from such heat treated bacterins
View Patent ↗Heat treated bacterins, a method of producing heat treated bacterins, and emulsion vaccines prepared from such heat treated bacterins are disclosed.
1. 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.
2. The immunogenic composition according to claim 1 wherein the bacterin is heated to a temperature of 55 to 65° C. for 5 to 8 hours.
3. The immunogenic composition according to claim 1 wherein the bacterin is heated to a temperature of 65 to 70° C. for 5 to 8 hours.
4. The immunogenic composition according to claim 1 wherein the bacterin is heated to a temperature of 65 to 70° C. for 1 hour.
5. The immunogenic composition according to claim 1 wherein the bacterin is heated to a temperature of 60 to 70° C. for 9 to 10 hours.
6. The immunogenic composition according to claim 1 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.
7. The immunogenic composition according to claim 1 , wherein said one or more emulsifiers is selected from the group consisting of lecithin, sorbitan monooleate, and polyethoxy sorbitan monooleate.
8. The immunogenic composition of claim 1 , wherein the heat treated bacterin is prepared by a method which comprises heating the bacterin to a temperature of 55 to 65° C. for 5 to 8 hours, or to a temperature of 65 to 70° C. for 5 to 8 hours, or to a temperature of 65 to 70° C. for 1 hour, or to a temperature of 60 to 70° C. for 9 to 10 hours.
9. The immunogenic composition of claim 1 , wherein the heat treated bacterin is prepared by a method comprising the steps of:
a) measuring the lipase activity of the bacterin;
b) heating the bacterin to a temperature of 55 to 65° C. for 5 to 8 hours, or to a temperature of 65 to 70° C. for 5 to 8 hours, or to a temperature of 65 to 70° C. for 1 hour, or to a temperature of 60 to 70° C. for 9 to 10 hours;
c) measuring the lipase activity of the bacterin after heat treatment;
d) comparing the lipase activity of the bacterin before heating to the lipase activity of the bacterin after heating; and
e) selecting a heat treated bacterin wherein the lipase activity after heat treatment is 50% or less of the lipase activity of the bacterin before heat treatment.
10. The immunogenic composition according to claim 1 , wherein the heat treated bacterin is prepared by a method comprising:
a) forming a Leptospira bacterin comprising a suspension of killed Leptospira bacteria having lipase activity; and
b) heating the Leptospira bacterin to a temperature of about 55 to about 80° C. for 1 to 10 hours to reduce the lipase activity to a level of 50% or less than the level before the heat treatment.
11. The immunogenic composition according to claim 10 , 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.
12. The immunogenic composition according to claim 1 , wherein the bacterin is heated to a temperature of 65° C. for 8 hours.
13. The immunogenic composition according to claim 1 , wherein the heat treated bacterin is non-viricidal.
14. The immunogenic composition according to claim 7 , further comprising Quil A and cholesterol.
15. The immunogenic composition according to claim 1 , wherein the lipase activity of said bacterin is above zero.