Abstract: The present invention relates, to novel methods and substrates for the propagation of viruses. The invention relates to IFN-deficient substrates and methods for propagating viruses in these unconventional substrates. In particular, the invention relates to methods of propagating viruses in immature embryonated eggs, preferably six- to nine-day-old chicken eggs. The methods of the invention are particularly attractive for growing viruses suitable for use in vaccine and pharmaceutical formulations.

Abstract: The present invention relates, in general, to attenuated negative-strand RNA viruses having an impaired ability to antagonize the cellular interferon (IFN) response, and the use of such attenuated viruses in vaccine and pharmaceutical formulations. The invention also relates to the development and use of IFN-deficient systems for selection of such attenuated viruses. In particular, the invention relates to attenuated influenza viruses having modifications to the NS1 gene that diminish or eliminate the ability of the NS1 gene product to antagonize the cellular IFN response. The mutant viruses replicate in vivo but demonstrate reduced pathogenicity, and therefore are well suited for live virus vaccines, and pharmaceutical formulations.

Abstract: The present invention relates to genetically engineered attenuated viruses and methods for their production. In particular, the present invention relates to engineering live attenuated viruses which contain a modified NS gene segment. Recombinant DNA techniques can be utilized to engineer site specific mutations into one or more noncoding regions of the viral genome which result in the down-regulation of one or more viral genes. Alternatively, recombinant DNA techniques can be used to engineer a mutation, including but not limited to an insertion, deletion, or substitution of an amino acid residue(s) or an epitope(s) into a coding region of the viral genome so that altered or chimeric viral proteins are expressed by the engineered virus.

Abstract: The present invention relates to genetically engineered attenuated viruses and methods for their production. In particular, the present invention relates to engineering live attenuated viruses which contain a modified NS gene segment. Recombinant DNA techniques can be utilized to engineer site specific mutations into one or more noncoding regions of the viral genome which result in the down-regulation of one or more viral genes. Alternatively, recombinant DNA techniques can be used to engineer a mutation, including but not limited to an insertion, deletion, or substitution of an amino acid residue(s) or an epitope(s) into a coding region of the viral genome so that altered or chimeric viral proteins are expressed by the engineered virus.

Abstract: The present invention relates to genetically engineered attenuated viruses and methods for their production. In particular, the present invention relates to engineering live attenuated viruses which contain a modified NS gene segment. Recombinant DNA techniques can be utilized to engineer site specific mutations into one or more noncoding regions of the viral genome which result in the down-regulation of one or more viral genes. Alternatively, recombinant DNA techniques can be used to engineer a mutation, including but not limited to an insertion, deletion, or substitution of an amino acid residue(s) or an epitope(s) into a coding region of the viral genome so that altered or chimeric viral proteins are expressed by the engineered virus.