CHARACTERIZATION OF THE VACCINIA MVA HEMAGGLUTININ GENE LOCUS AND ITSEVALUATION AS AN INSERTION SITE FOR FOREIGN GENES

The 'Modified Vaccinia Ankara' (MVA) strain is a potential live vaccin e vector. The use of the hemagglutinin (ha) gene of the MVA strain as an insertion site for foreign genes was evaluated. To identify the mol ecular basis of the hemagglutinin-negative (HA(-)) phenotype of MVA, t he ha gene and the region around this gene were sequenced. Amino acid (aa) sequence comparisons with functional hemagglutinins of other vacc inia strains predicted a functional polypeptide. The late part of the promoter region of the ha gene, however, was deleted, causing the appa rent loss of the ha gene function. Nevertheless, insertion of foreign DNA into the ha gene allowed generation of functional recombinant viru ses, indicating that the ha-gene region is a suitable insertion site.