Dual adjuvant vaccine compositions, preparation and uses

1. A vaccine comprising an effective amount of at least one antigen and an adjuvant compound in a water-in-oil-in-water (WOW) emulsion, wherein the adjuvant compound is aluminum hydroxide, the at least one antigen is an inactivated salmonella bacterium, the WOW emulsion contains oily particles, at least 80% of the oily particles have a size between 3 and 20 μm and at least 60% (w/w) of the total amount of said at least one antigen in the vaccine is contained in the oily particles.

2. The vaccine according to claim 1 , wherein said WOW emulsion further comprises at least one surfactant.

3. The vaccine according to claim 1 , wherein the oily particles comprise a vegetable oil, an animal oil, a mineral oil, or a mixture thereof.

4. The vaccine according to claim 2 , wherein the at least one surfactant is polyoxyethylene sorbitan monooleate or sorbitan monooleate.

5. The vaccine according to claim 1 , wherein the WOW emulsion contains water vesicles embedded within the oily particles, said oily particles being dispersed in an outer aqueous phase.

6. The vaccine according to claim 5 , wherein between 60% and 75% (w/w) of the total amount of said at least one antigen in the vaccine is contained in the oily particles.

7. The vaccine according to claim 5 , wherein the adjuvant compound is in the outer aqueous phase.

8. The vaccine according to claim 1 , wherein said vaccine is obtainable by a process comprising:

a) emulsifying a solution of said at least one antigen in an oil base, thereby forming a water-in-oil (WO) emulsion,

b) adding said WO emulsion to a dispersal phase, thereby forming a WOW emulsion and emulsifying said WOW emulsion, the WOW emulsion comprising oily particles, and

c) mixing said WOW emulsion with the adjuvant compound, wherein at least 60% (w/w) of the total amount of said at least one antigen in the vaccine is contained in the oily particles.

9. A process for the preparation of a vaccine of claim 1 , the process comprising the steps of:

a) emulsifying a solution of said at least one antigen in an oil base, thereby forming a WO emulsion,

b) adding said WO emulsion to a dispersal phase, thereby forming a WOW emulsion and emulsifying said WOW emulsion, and

c) mixing said WOW emulsion with an adjuvant compound.

10. A method for vaccinating a non-human animal comprising administering to the animal an effective amount of a vaccine of claim 1 .

11. The vaccine according to claim 1 , wherein the salmonella bacterium is Salmonella enteritidis, Salmonella kentucky, Salmonella typhimurium, Salmonella heidelberg , or a combination thereof.

12. The vaccine according to claim 3 , wherein the oily particles comprise a mineral oil.

13. The vaccine according to claim 1 ,

wherein

at least 90% of the oily particles in the WOW emulsion have a size between 3 and 20 μm;

the vaccine has an OD600/ml superior to 4; and

at least 60% (w/w) of the total amount of said at least one antigen is contained in the oily particles and the rest of said at least one antigen is in the outer aqueous phase with said adjuvant compound.