Viral preparations, immunogens, and vaccines

摘要

The invention provides a mutant virus having a genome which is (a) defective in respect of a first gene, which is essential for the production of infectious virus, so that the virus can infect normal cells and undergo replication and expression of viral antigen genes in those cells but cannot produce infectious new virus particles therefrom, and (b) structurally or functionally inactivated in respect of a second gene, native to the virus and normally functioning to downregulate a host immune response against the corresponding wild-type virus. The mutant viruses are produced by culture on complementing cell lines expressing the first gene: they are of use e.g. as immunogens and vaccines and for stimulating cytotoxic T cells, e.g. in vitro.