Vaccines with enhanced immune response and methods for their preparation

Abstract

The present invention is concerned with vaccines and their preparation. An effective long-term immune response, especially in mammals, can be produced using a vaccine comprising an antigen encapsulated in liposomes, a suitable adjuvant and a carrier comprising a continuous phase of a hydrophobic substance. The vaccine is particularly effective in eliciting the production of antibodies that recognize epitopes of native proteins.

1 - 17 . (canceled)  
     
     
         18 . A method for potentiating an immune response in an animal, which method comprises administering to the animal an effective amount of a vaccine composition comprising: 
 (a) a carrier comprising a continuous phase of a hydrophobic substance;    (b) liposomes;    (c) an antigen encapsulated in said liposomes, said antigen being an antigen which when not in said vaccine composition has, a conformation other than its native conformation, with the proviso that said antigen is other than a zona pellucida-derived antigen; and    (d) a suitable adjuvant.    
     
     
         19 . The method of  claim 18 , wherein the hydrophobic substances is a liquid.  
     
     
         20 . The method of  claim 18 , wherein the carrier is an oil or a water-in-oil emulsion.  
     
     
         21 . The method of  claim 20 , wherein the oil is mineral oil, a vegetable oil or a nut oil.  
     
     
         22 . The method of  claim 21 , wherein the adjuvant is alum or another compound of aluminum  
     
     
         23 . The method of  claim 21 , wherein the antigen is alcohol dehydrogenase, or a hepatitis B antigen  
     
     
         24 . The method of  claim 20 , wherein the antigen elicits an antibody that recognizes a native epitope.  
     
     
         25 . The method of  claim 24 , wherein the native epitope is a mammalian epitope.  
     
     
         26 . The method of  claim 25 , wherein the mammal is a horse, a rabbit, a deer or a cat.  
     
     
         27 . The method of  claim 20 , wherein the composition is substantially free of lipid A.  
     
     
         28 - 43 . (canceled)  
     
     
         44 . The method of  claim 22 , wherein the adjuvant is alum.  
     
     
         45 . The method of  claim 20 , wherein the antigen is a non-native, recombinant or denatured protein, a recombinant or synthetic peptide, or a fragment thereof.  
     
     
         46 . The method of  claim 45 , wherein the antigen is a viral, bacterial, protozoal or mammalian antigen.  
     
     
         47 . The method of  claim 20 , wherein the liposomes comprise unesterified cholesterol and a phospholipid with at least one head group selected from the group consisting of phosphoglycerol, phosphoethanolamine, phosphoserine, phosphocholine and phosphoinositol.  
     
     
         48 . The method of  claim 18 , wherein said vaccine composition is administered parenterally.  
     
     
         49 . The method of  claim 18 , wherein said animal is a horse, rabbit, deer or cat.