EIA vaccine and diagnostic

Abstract

The invention provides an equine infectious anemia (EIA) vaccine that provides immunity to mammals, especially equines, from infection with equine infectious anemia virus (EIAV) and which allows differentiation between vaccinated and non-vaccinated, but exposed, mammals or equines. Preferably said vaccine encompasses at least one mutation in an EIAV which produces a non-functional gene in the vaccine virus that is always expressed in disease-producing wild-type EIA viruses. Additionally, said EIA vaccine virus cannot cause clinical disease in mammals or spread or shed to other mammals including equines.

What is claimed is:  
     
         1 . A vaccine for effectively and safely immunizing mammals from disease caused by EIAV, said vaccine comprising a gene-mutated EIAV wherein said virus-lacks the ability to express the mutated gene protein in vivo and wherein said lack of expression can be used to differentiate vaccinated from non-vaccinated or infected mammals.  
     
     
         2 . The vaccine of  claim 1  wherein said gene-mutated EIAV comprises a mutation in at least one accessory gene.  
     
     
         3 . The vaccine of  claim 2  wherein said accessory gene is an S2 gene.  
     
     
         4 . The vaccine of  claim 1  wherein said gene-mutated EIAV comprises a mutation in a DU gene.  
     
     
         5 . The vaccine of  claim 4  wherein said mutation in the DU gene is a deletion.  
     
     
         6 . The vaccine of  claim 1  wherein the gene-mutated EIAV comprises at least two mutations.  
     
     
         7 . The vaccine of  claim 6  wherein the two mutations are in the S2 and DU genes.  
     
     
         8 . The vaccine of  claim 7  wherein the two mutations in the S2 and DU genes are deletions.  
     
     
         9 . The vaccine of  claim 5  wherein a foreign gene or a foreign gene portion is inserted into the DU gene deletion.  
     
     
         10 . The vaccine of  claim 7  wherein a foreign gene or a foreign gene portion is inserted into the S2 gene deletion.  
     
     
         11 . The vaccine according to  claim 1  wherein the gene-mutated EIAV is treated with an inactivating agent.  
     
     
         12 . The vaccine according to  claim 11  wherein the inactivating agent is selected from the group consisting of formalin, formaldehyde, beta-propiolactone, binary ethylenimine, ethylenimine, thimerosal, psoralen and heat.  
     
     
         13 . A vaccine for protecting horses from disease caused by EIAV comprising a gene-mutated EIAV construct, said construct allowing a vaccinated horse to be differentiated from an EIAV infected horse.  
     
     
         14 . The vaccine of  claim 13 , wherein the gene-mutated EIAV construct comprises a deletion in the S2 and/or the DU genes.  
     
     
         15 . A diagnostic test for differentiating mammals vaccinated with the vaccine of  claim 1  from non-vaccinated mammals or from infected mammals-comprising one or more reagents for demonstrating the absence of a normal EIAV gene expression product in mammals vaccinated with the gene-mutated vaccine of  claim 1  and a measurable level of said expression product in infected mammals.  
     
     
         16 . A diagnostic test for differentiating mammals vaccinated with the vaccine of  claim 1  from non-vaccinated mammals or from infected mammals comprising one or more reagents for demonstrating the absence of a normal gene sequence in mammals vaccinated with the gene-mutated vaccine of claims  1  and a measureable amount of the normal gene sequence in infected mammals.  
     
     
         17 . A method of differentiating a vaccinated mammal from a non-vaccinated mammal, said method comprising; 
 a. obtaining a sample from a test mammal; and    b. analyzing said sample for the presence of a gene expression product normally produced by wild-type EIAV but not produced by an EIAV construct used for vaccinating said test mammal.    
     
     
         18 . A method of differentiating a vaccinated mammal from a non-vaccinated mammal, said method comprising; 
 c. obtaining a sample from a test mammal; and    d. analyzing said sample for the presence of a gene sequence normally present in wild-type EIAV but not present in an EIAV construct used for vaccinating said test mammal.    
     
     
         19 . A method of immunizing a horse against EIAV comprising vaccinating said horse with an EIAV vaccine comprising a gene-mutated EIAV and an adjuvant.  
     
     
         20 . A method of immunizing a horse against EIAV comprising vaccinating said horse with an EIAV vaccine comprising a gene-mutated EIAV, an inactivating agent and an adjuvant