Canine vaccine for protection against ehrlichiosis

Abstract

The present invention provides a safe and effective vaccine composition which comprises: an effective immunizing amount of an inactivated Ehrlichia canis bacterin; a pharmacologically acceptable carrier; and an immunogenically stimulating amount of an adjuvant system consisting essentially of an antibody response inducing agent and a cell-mediated immunity response inducing agent. The present invention also provides a method for the prevention or amelioration of canine ehrlichiosis in dogs.

1 . A vaccine composition which comprises: an effective immunizing amount of an inactivated  Ehrlichia canis  bacterin; a pharmacologically acceptable carrier; and an immunogenically stimulating amount of an adjuvant system consisting essentially of an antibody response inducing agent and a cell-mediated immunity response inducing agent.  
     
     
         2 . The composition according to  claim 1  wherein said inactivated bacterin is selected from the group consisting of one or more  E. canis  strains designated as Ebony, Florida, Israel 611, Kogashima 1, Louisiana, Oklahoma, Venezuela, the North Carolina State University (NCSU) strain Jake, the NCSU isolates Demon, DJ and Fuzzy,  E. canis  infected cell lines with any of the designated strains, and  E. canis  infected DH82 cell lines with any of the designated strains.  
     
     
         3 . The composition according to  claim 1  wherein said inactivated bacterin is selected from the group consisting of  Ehrlichia canis  Ebony, Ehrlichia canis Broadfoot and a mixture thereof.  
     
     
         4 . The composition according to  claim 1  wherein the antibody response inducing agent is selected from the group consisting of ethylene maleic anhydride; styrenated acrylic copolymer; and a mixture thereof.  
     
     
         5 . The composition according to  claim 1  wherein the cell-mediated immunity response inducing agent is selected from the group consisting of an oil-in-water emulsion; a Th-1-related cytokine; an attenuated  Mycobacterium bovis ; and a mixture thereof.  
     
     
         6 . The composition according to  claim 2  wherein said inactivated bacterin is present in sufficient quantity to provide at least 1×10 4  TCID 50  per unit dose.  
     
     
         7 . The composition according to  claim 4  wherein the antibody response inducing agent is a mixture of ethylene maleic anhydride and a styrenated acrylic copolymer and is present in the amount of about 1% vol/vol ethylene maleic anhydride and about 3% vol/vol styrenated acrylic copolymer.  
     
     
         8 . The composition according to  claim 5  wherein said oil-in-water emulsion is selected from the group consisting of a paraffin oil-in-water emulsion; a composition of squalane and block copolymers of ethylene oxide and propylene oxide; Syntex Adjuvant Formulation-1; and a mixture thereof.  
     
     
         9 . The composition according to  claim 5  wherein said Th1-related cytokine is selected from the group consisting of interleukin-12; interleukin-18; gamma interferon; and a mixture thereof.  
     
     
         10 . The composition according to  claim 5  wherein said cell-mediated immunity response agent is an oil-in-water emulsion and is present in a range of about 3% to 7% vol/vol.  
     
     
         11 . The composition according to  claim 5  wherein said cell-mediated immunity response agent is an oil-in-water emulsion and is present in an amount of about 5% vol/vol.  
     
     
         12 . A method for the prevention or amelioration of canine ehrlichiosis in a dog, which comprises administering to said dog a vaccine composition which comprises an effective immunizing amount of an inactivated  Ehrlichia canis  bacterin; a pharmacologically acceptable carrier; and an immunogenically stimulating amount of an adjuvant system consisting essentially of an antibody response inducing agent and a cell-mediated immunity response inducing agent.  
     
     
         13 . The method according to  claim 12  having a vaccine composition wherein said inactivated bacterin is selected from the group consisting of one or more  E. canis  strains designated as Ebony, Florida, Israel 611, Kogashima 1, Louisiana, Oklahoma, Venezuela, the North Carolina State University (NCSU) strain Jake, the NCSU isolates Demon, DJ and Fuzzy,  E. canis  infected cell lines with any of the designated strains, and  E. canis  infected DH82 cell lines with any of the designated strains.  
     
     
         14 . The method according to  claim 12  having a vaccine composition wherein said inactivated bacterin is  Ehrlichia canis  Ebony or  Ehrlichia canis  Broadfoot or a mixture thereof.  
     
     
         15 . The method according to  claim 12  having a vaccine composition wherein the antibody response-inducing agent is a mixture of ethylene maleic anhydride and a styrenated acrylic copolymer.  
     
     
         16 . The method according to  claim 12  having a vaccine composition wherein the cell-mediated immunity response inducing agent is selected from the group consisting of a paraffin oil-in-water emulsion; a composition of squalane and block copolymers of ethylene oxide and propylene oxide; Syntex Adjuvant Formulation-1; an attenuated  Mycobacterium bovis ; interleukin-12; interleukin-18; gamma interferon; and a mixture thereof.  
     
     
         17 . The method according to  claim 12  having a vaccine composition wherein said inactivated bacterin is present in sufficient amount to provide at least 1×10 4  TCID 50  per unit dose.  
     
     
         18 . A method for the induction of clinical canine ehrlichiosis in a test animal which comprises administering to said test animal an effective amount of a challenge stock consisting essentially of peripheral blood mononuclear cells infected with a virulent  Ehrlichia canis  microorganism.  
     
     
         19 . The method according to  claim 18  wherein said stock solution is administered subcutaneously.  
     
     
         20 . The method according to  claim 18  wherein said virulent microorganism is produced by the repeated passage thereof in a test animal.  
     
     
         21 . The method according to  claim 20  wherein said microorganism is  Ehrlichia canis  Ebony.  
     
     
         22 . A challenge stock composition that comprises peripheral blood mononuclear cells infected with a virulent  Ehrlichia canis  microorganism.  
     
     
         23 . The composition according to  claim 22  wherein said virulent microorganism is  Ehrlichia canis  Ebony that has been repeatedly passaged in a test animal.