Method to prevent fertilization in mammals by administering a single dose of zona pellucida derived antigens, liposome and adjuvant

Abstract

A vaccine for the immunocontraception of mammals is described. The vaccine consists of zona pellucida antigens and an adjuvant encapsulated in a liposome delivery system. The liposome delivery system allows for the slow release of antigen resulting in a prolonged immune response. In particular, after a single injection of the vaccine, levels of anti-zona pellucida antibodies were detected for up to 22 months in seals. Thus, the vaccine according to the present invention is effective after a single dose and is therefore very useful in immunocontraceptive protocols.

We claim:  
     
       1. A method of preventing fertilization in a mammal for at least twelve months which method consists of a single parenteral administration of an effective amount of a vaccine composition comprising a zona pellucida derived antigen and a Freund's adjuvant in a liposome formulation. 
     
     
       2. A method according to claim  1  wherein said zona pellucida derived antigen is ZP3. 
     
     
       3. A method according to claim  1  wherein said zona pellucida derived antigen is solubilized intact zona pellucida. 
     
     
       4. A method according to claim  1  wherein said zona pellucida derived antigen is porcine derived. 
     
     
       5. A method according to claim  1  wherein said liposome formulation is freeze-dried. 
     
     
       6. A method according to claim  1  wherin said mammal is a seal. 
     
     
       7. A method of preventing fertilization in a seal for at least  12  months which method consists of a single parenteral administration of an effective amount of a vaccine composition comprising a zona pellucida derived antigen and an adjuvant effective in enhancing the immune response to the vaccine composition, in a liposome formulation.  
     
     
       8. The method according to claim  7  wherein said zona pellucida derived antigen is ZP  3 .  
     
     
       9. The method according to claim  7  wherein said zona pellucida derived antigen is solubilized intact zona pellucida.  
     
     
       10. The method according to claim  7  wherein said zona pellucida derived antigen is porcine derived.  
     
     
       11. The method according to claim  7  wherein said liposome formulation is freeze- dried.    
     
     
       12. The method according to claim  7  wherein said adjuvant is Freund's adjuvant.  
     
     
       13. A method for preventing fertilization in a mammal for up to at least  22  months which method consists of a single parenteral administration of an effective amount of a vaccine composition comprising a zona pellucida derived antigen and an adjuvant effective in enhancing the immune response to the vaccine composition, in a liposome formulation.  
     
     
       14. The method according to claim  13  wherein fertilization is prevented for up to  22  months.  
     
     
       15. The method according to claim  14  wherein said zona pellucida derived antigen is ZP  3 .  
     
     
       16. The method according to claim  14  wherein said zona pellucida derived antigen is solubilized intact zona pellucida.  
     
     
       17. The method according to claim  14  wherein said zona pellucida derived antigen is porcine derived.  
     
     
       18. The method according to claim  14  wherein said liposome formulation is freeze- dried.    
     
     
       19. The method according to claim  14  wherein said mammal is a seal.  
     
     
       20. The method according to claim  14  wherein said adjuvant is Freund's adjuvant.  
     
     
       21. The method according to claim  13  wherein said zona pellucida derived antigen is ZP  3 .  
     
     
       22. The method according to claim  13  wherein said zona pellucida derived antigen is solubilized intact zona pellucida.  
     
     
       23. The method according to claim  13  wherein said zona pellucida derived antigen is porcine derived.  
     
     
       24. The method according to claim  13  wherein said liposome formulation is freeze- dried.    
     
     
       25. The method according to claim  13  wherein said mammal is a seal.  
     
     
       26. The method according to claim  13  wherein said adjuvant is Freund's adjuvant.