Superior molecular vaccines comprise nucleic acids, including naked DNA
and replicon RNA, that encode a fusion polypeptide that includes an
antigenic peptide or polypeptide against which an immune response is
desired. Fused to the antigenic peptide is an intercellular spreading
protein, in particular a herpes virus protein VP22 or a homologue or
functional derivative thereof. Preferred spreading proteins are VP22 from
HSV-1 and Marek's disease virus. The nucleic acid can encode any
antigenic epitope of interest, preferably an epitope that is processed
and presented by MHC class I proteins. Antigens of pathogenic organisms
and cells such as tumor cells are preferred. Vaccines comprising HPV-16
E7 oncoprotein are exemplified. Also disclosed are methods of using the
vaccines to induce heightened T cell mediated immunity, in particular by
cytotoxic T lymphocytes, leading to protection from or treatment of a
tumor.