Vectors based on recombinant defective viral genomes and their use in the formulation of vaccines

Abstract

The vectors comprise a recombinant defective viral genome expressing at least one antigen suitable for the induction of systemic and secretory immune responses or an antibody conferring protection against an infectious agent. The defective viral genome comprises the genome of a parental virus having the viral replicase recognition signals located on ends 3′ and 5′, further comprising internal deletions, and wherein said defective viral genome depends on a helper virus for its replication and encapsidation. These vectors are suitable for the forming of a recombinant system comprising the aforesaid expression vector, and a helper virus. The system is suitable for the manufacture of mono- and polyvalent vaccines against infectious agents of different animal species, especially pigs, dogs and cats, and as expression vehicles for antibodies protective against infectious agents.

1 - 45 . (canceled)  
     
     
         46 . A bovine vaccine against a pathogen of interest, wherein the vaccine comprises a helper virus, at least one recombinant virion, and a pharmaceutical excipient, wherein the recombinant virion(s) comprises: 
 (A) at least 1.9 kb of the 5′ end of a TGEV genome;    (B) the pseudoknot region, including the region of overlap between ORFs 1a and 1b, of the TGEV genome;    (C) incomplete S, M, and N structural genes of the TGEV genome;    (D) at least bp 9691-9707 of the 3′ end of the TGEV genome; and    (E) at least one heterologous gene sequence encoding an antigen of the pathogen of interest inserted under the control of the S gene promoter of the TGEV genome.    
     
     
         47 . The vaccine as claimed in  claim 46 , wherein the pathogen has a tropism for enteric or respiratory mucosae.  
     
     
         48 . The vaccine as claimed in  claim 46 , wherein the vaccine comprises more than one recombinant virion.  
     
     
         49 . The vaccine as claimed in  claim 46 , wherein the virion comprises more than one heterologous gene sequence encoding an antigen of an infectious agent that infects bovine species.  
     
     
         50 . A bovine vaccine against a pathogen of interest, wherein the vaccine comprises at least one recombinant virion and a pharmaceutical excipient, wherein the recombinant virion(s) is prepared according to the method comprising: 
 (A) constructing a recombinant plasmid comprising a defective TGEV genome under the control of an RNA polymerase promoter, wherein the defective TGEV genome comprises: 
 (1) at least 1.9 kb of the 5′ end of the TGEV genome;  
 (2) the pseudoknot region, including the region of overlap between ORFs 1a and 1b, of the TGEV genome;  
 (3) incomplete S, M, and N structural genes of the TGEV genome;  
 (4) at least bp 9691-9707 of the 3′ end of the TGEV genome; and  
 (5) at least one heterologous gene sequence encoding an antigen of the pathogen of interest inserted under the control of the S gene promoter of the TGEV genome;  
   (B) producing RNA of the sequences in (A) by transcribing the sequences from the RNA polymerase promoter;    (C) infecting cells with a helper virus;    (D) introducing the RNA produced in step (B) into the infected cells of step (C); and    (E) producing a recombinant virion comprising a defective TGEV genome and the heterologous gene under the control of the S gene promoter of the TGEV genome.    
     
     
         51 . The vaccine as claimed in  claim 50 , wherein the pathogen has a tropism for enteric or respiratory mucosae.  
     
     
         52 . The vaccine as claimed in  claim 50 , wherein the vaccine comprises more than one recombinant virion.  
     
     
         53 . The vaccine as claimed in  claim 50 , wherein the virion comprises more than one heterologous gene sequence encoding an antigen of an infectious agent that infects bovine species.