A method for producing reassortant influenza viruses is provided. Also provided are reassortant influenza viruses produced according to the method, as well as vaccines based on said reassortant influenza viruses.

In a first aspect, the present invention relates to a method for the purification of virus compositions as well as biological macromolecular compounds in a sample comprising mixing the sample with osmolytes, like non-ionic organic polymers and contacting the mixed sample with a hydrophilic membrane, optionally washing the membrane, and eluting the virus preparations or biological macromolecular components from the membrane with an eluting solution containing reduced amounts or no osmolytes, like non-ionic organic polymer. Moreover, virus compositions and biological macromolecular components obtainable with the method according to the present invention are provided as well as the use of the method according to the present invention for purification of virus compositions including whole virus particles and virus-like particles or biological macromolecular components.

The present disclosure discloses a whole avian-origin reverse genetic system, a recombinant H5N2 subtype avian influenza virus, a vaccine containing the virus, and a preparation method and application thereof. The genome of the recombinant virus is comprised of a modified HA gene derived from a highly pathogenic H5N6 subtype avian influenza virus strain, as well as PB2, PB1, PA, NP, NA, M and NS genes derived from H5N2 subtype avian influenza D7 virus strain. The recombinant virus is a recombinant H5N2 avian influenza virus rescued from the D7 virus strain as a backbone, which is an avirulent virus strain with the original immunogenicity, and can maintain a high virus titer during the chick embryo culture process. The recombinant virus fully meets the biological safety requirements and has a good application prospect.

A heat-resistant H1N1 subtype influenza virus mutant strain rPR8-HA-N5 has been preserved at China Center for Type Culture Collection, Wuhan University, Wuhan, China with the preservation number of CCTCC No. V202043.

Disclosed herein are compositions and methods related to mutant viruses, and in particular, mutant influenza viruses. The mutant viruses disclosed herein include a mutant M2 sequence, and are useful in immunogenic compositions, e.g., as vaccines. The mutant viruses disclosed herein including a mutant M2 sequence are also useful to deliver antigens to a subject, e.g., to induce an immune response to the antigen. Also disclosed herein are methods, compositions and cells for propagating the viral mutants, and methods, devices and compositions related to vaccination.

A method for adapting an influenza virus to Vero cells is provided. The method comprises infecting Vero cells with the influenza virus, cultivating the infected Vero cells, harvesting influenza viruses of each passage, wherein infectious dose of the influenza viruses of one passage is greater than or equal to infectious dose of the influenza viruses of a previous passage. The present disclosure also relates to a composition. Said composition comprises polyriboinosinic acid-polyribocytidylic acid, at least one antibiotic or polyamide compound, at least one positive ion, influenza viruses and/or influenza antigens, wherein said influenza viruses and/or influenza antigens are acquired from Vero cell adapted influenza viruses.

Disclosed are compositions and methods for increasing virus production. In particular, disclosed herein are cell or cell line comprises reduced expression of one or more cellular genes selected from the group comprising COQ9, FGF2, NAT9, NDUFA9, NEU2, PLA2G1B, PYCR1, RAD51AP1, STRADA, SVOPL, and/or ZFYVE9 for use in increasing viral production.

A suprastructure comprising a modified influenza hemagglutinin (HA) is provided. The modified HA may comprise one or more than one alteration that reduces non-cognate binding of the modified HA to sialic acid (SA) on the surface of a cell, while maintaining cognate interaction with the cell, such as a B cell. A composition comprising the suprastructure and modified HA and a pharmaceutically acceptable carrier is also described. A method of increasing an immunological response or inducing immunity in response to a vaccine comprising the suprastructure and modified HA is also provided.

An isolated recombinant influenza virus is provided having PA, PB1, PB2, NP, NS, M, NA and HA viral segments, wherein the PB1 viral segment encodes a PB1 with a residue other than isoleucine at position 711 or the M viral segment encodes a M1 with a residue other than methionine at position 128, wherein the recombinant influenza virus has enhanced replication relative to a corresponding influenza virus having a PB1 viral segment that encodes a PB1 with an isoleucine at position 711 or having a M viral segment that encodes a M1 with methionine at position 128, as well as methods of making and using the virus.

Disclosed herein are compositions and methods related to mutant viruses, and in particular, mutant influenza viruses. The mutant viruses disclosed herein include a mutant M2 sequence, and are useful in immunogenic compositions, e.g., as vaccines. The mutant viruses disclosed herein including a mutant M2 sequence are also useful to deliver antigens to a subject, e.g., to induce an immune response to the antigen. Also disclosed herein are methods, compositions and cells for propagating the viral mutants, and methods, devices and compositions related to vaccination.