Immunogenicity of recombinant vaccinia viruses expressing hepatitis B virus surface antigen in mice.

The ability of different recombinant vaccinia viruses (RVV) expressing hepatitis B virus surface antigen (HBsAg) to induce anti-HBs and anti-vaccinia virus responses has been analyzed in mice. The RVVs tested differed with regard to the original vaccinia virus strain used as vector and the site of insertion of a foreign gene. It was found that the immunological responses to RVVs based on the WR strain were higher than those to RVVs based on the Lister strain. The immunological response was also quantitatively affected by the viral TK phenotype. The presence of the preS2 region in HBsAg gene, inserted into the RVV genome, led to the induction of anti-preS2 antibodies but decreased the antibody response to the S-portion of HBsAg.