Methods to Increase Stability of Recombinant Vaccinia-Vectored Vaccines and Increase Expression of a Foreign Gene Inserted in Such Vaccines

The technology offered for licensing is in the field of vaccinia-based recombinant vaccines. In particular the invention relates to methods of stabilizing the recombinant virus, thus resulting in efficient production of the vaccine and efficient expression of the inserted gene. Stabilization of the recombinant virus is achieved by the insertion of the exogenous gene into an intergenic region (IGR) of the viral genome (i.e. Modified Vaccinia Ankara, MVA), where the IGR is flanked by open reading frames of conserved poxvirus genes. Furthermore, the invention relates to plasmids vectors useful to insert the exogenous DNA into the genome of a vaccinia virus. Stability can be further enhanced by incorporating silent mutations that decrease the lengths of homopolynucleotide runs in the foreign gene.