The present invention provides a method for purification of a virus or virus antigen comprising providing a virus preparation and centrifugation of said virus preparation in a gradient of a sugar established by the addition of two or more buffered sugar layers of different concentration. The method leads to higher yields and reduces unwanted aggregation of the virus or virus antigen by increasing the volume of the peak pool.

The present invention relates to a new method for rescuing an influenza virus and a composition therefor. The method comprises providing a host cell stably integrated with and expressing influenza virus PA, PB1, PB2 and NP genes, and introducing an influenza virus rescue system in which a stop codon is introduced into the PA, PB1, PB2 and NP genes respectively into the host cell to achieve virus rescue. The produced virus particles can be used as a live attenuated influenza vaccine, which is characterized in that, since the genes encoding the related proteins are mutated, it has no replication and proliferation ability in human and normal animal cells, and replication and proliferation can be achieved only in the host cells constructed above and it can fully stimulate the body immunity and effectively protect the body while ensuring the safety.

The present invention relates to the production of modified influenza viral proteins in plants. More specifically, the present invention relates to producing and increasing influenza virus-like particle (VLP) production in plants, wherein the VLPs comprise the modified influenza viral proteins, such as modified influenza hemagglutinin (HA). The HA protein may comprising an amino acid sequence comprising at least one substitution when compared to a corresponding wildtype amino acid sequence. Further provided are nucleic acid encoding the modified HA protein. Furthermore methods of producing an influenza virus like particle (VLP) and methods of increasing yield of production of an influenza virus like particle (VLP) in a plant, portion of a plant, or a plant cell, are also provided.

Provided are compounds of Formula (II) that enhance the efficacy of viruses by increasing spread of the virus in cells, increasing the titer of virus in cells, or increasing the antigen expression from a virus, gene or trans-gene expression from a virus, or virus protein expression in cells. Other uses, compositions and methods of using same are also provided. ##STR00001##

The present invention refers to a process for purifying virus particles from cell culture, comprising the steps of subjecting the cell culture to centrifugation to get a supernatant fraction of virus particles, incubating said fraction with a nuclease, diluting the fraction with low conductivity buffer, subjecting said diluted fraction to a SO3 chromatography step, performing a washing step with low conductivity buffer, and eluting virus particles.

The present invention provides, among other things, a novel and improved method for generating “mosaic” influenza antigenic polypeptides including hemagglutinin (HA) and neuraminidase (NA) polypeptides based on unique combination of epitope patterns that maximize exposure to epitopes present across multiple HA or NA sequences and therefore improved influenza strain coverage. In particular, the present invention provides engineered H1N1 influenza hemagglutinin (HA) polypeptides that are comprised of novel combinations of protective epitopes and antigenic regions from multiple H1N1 viral strains. Such engineered HA polypeptides have improved properties over HA polypeptides developed through conventional approaches that rely on consensus alignments of viral sequences.

Compositions and methods to prepare influenza virus-like particles (VLPs) are provided.

The invention relates to the field of veterinary medicine. The invention provides an immunogenic composition, comprising a hemagglutinin protein of avian influenza virus H5 subtype. Also provided is a method of differentiating animals naturally infected with AIV from animals vaccinated with the immunogenic composition of the invention. The immunogenic composition of the invention can provide a broader, more effective, long-lasting and early onset protection on poultry.

The present invention relates to methods of replicating viruses in vitro. In particular, the invention relates to a genetically modified population of cells, and/or a population of cells treated with an exogenous compound, wherein the cells are capable of producing more virus than cells lacking the genetic modification and/or lacking treatment with the exogenous compound. The invention also relates to methods of producing populations of such cells, as well as the use of the viruses obtained to prepare vaccine compositions.

The present invention relates to the production of modified influenza vial proteins in plants. More specifically, the present invention relates to producing and increasing influenza virus-like particle (VLP) production in plants, wherein the VLPs comprise the modified influenza viral proteins, such as modified influenza hemagglutinin (HA). The H A protein may comprising an amino acid sequence comprising at least one substitution when compared to a corresponding wildtype amino acid sequence. Further provided are nucleic acid encoding the modified H A protein. Furthermore methods of producing an influenza virus like particle (VLP) and methods of increasing yield of production of an influenza virus like particle (VLP) in a plant, portion of a plant, or a plant cell, are also provided.