The present invention discloses a replication-limited mucosal immune vaccine for influenza virus. The present invention first protects a mutant protein, which is obtained by mutating two amino acid residues of NS1 protein of influenza virus as follows: the amino acid residue at position 38 is mutated from arginine to alanine, and the amino acid residue at position 41 is mutated from lysine to alanine. The present invention also protects a recombinant virus, which is obtained by mutating the codons encoding two amino acid residues of NS1 protein in the influenza virus genome as follows: the codon for the amino acid residue at position 38 from the N-terminus is mutated from the arginine codon to an alanine codon, and the codon for the amino acid residue at position 41 from the N-terminus is mutated from the lysine codon to an alanine codon. The present invention also protects use of any one of the above-mentioned recombinant viruses for preparing a vaccine for influenza virus. The present invention has great application value for the prevention and treatment of influenza virus.

The present invention relates to vaccine products for the treatment or prevention of viral infections. Further provided are methods of reducing contaminants associated with the preparation of cell culture vaccines. Residual functional cell culture DNA is degraded by treatment with a DNA alkylating agent, such as -propiolactone (BPL), thereby providing a vaccine comprising immunogenic proteins derived from a virus propagated on cell culture, substantially free of residual functional cell culture DNA.

Provided are compounds 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.

The subject invention pertains to isolated influenza virus that is capable of infecting canids and causing respiratory disease in the canid. The subject invention also pertains to compositions and methods for inducing an immune response against an influenza virus of the present invention. The subject invention also pertains to compositions and methods for identifying a virus of the invention and diagnosing infection of an animal with a virus of the invention.

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.

Described are methods for preparing virosomes comprising the steps of: (a) providing an enveloped virus, and optionally inactivating the virus; (b) solubilizing the viral envelopes in a first solubilizing agent; (c) pre-solubilizing exogenous components in a second solubilizing agent; (d) adding the pre-solubilized exogenous components to the solubilized viral envelopes; and (e) reconstituting virosomal membranes by removing the solubilizing agent. According to the disclosure, the viral envelopes and the exogenous components are (pre-)solubilized at a temperature below 33 C.

Provided is an application of a label gene sequence in the preparation of an H9 avian influenza vaccine strain which differentiates influenza A virus infection from vaccination, the label gene sequence containing a DNA sequence for coding an influenza B virus NA protein extracellular region amino acid sequence. Also provided are an H9 avian influenza vaccine strain which differentiates influenza A virus infection from vaccination, a preparation method therefor, and an application.

Embodiments relate to a method comprising (a) expressing a vector comprising a PSGL-1 (P-selectin glycoprotein ligand-1) or a mutant thereof in a VPC (virus producing cell); and blocking a virus infection by inactivating an infectivity of a released virions from the VPC; or (b) expressing a glycoprotein or a mutant thereof in the VPC; blocking the virus infection by preventing binding of the released virions to a target cell; inactivating infectivity of the released virions; and targeting a viral infection. Other embodiments relate to (1) a broad-spectrum anti-viral product comprising: a vector expressing a glycoprotein or a mutant thereof in a VPC; and blocking a virus infection by inactivating infectivity of a released virion from the VPC; and (2) a vaccine comprising a viral particle is configured to a live attenuated or an inactivated or a non-infectious, wherein the viral particle are produced in a VPC.

The invention provides a carrier and a method for obtaining, removing, or detecting extracellular membrane vesicle or virus present in a sample. In particular, the invention provides (a) a carrier (a Tim carrier) on which a protein (a Tim protein), selected from a T-cell immunoglobulin and mucin domain-containing molecule-4 (a Tim-4) protein, a Tim-3 protein, and a Tim-1 protein, is bound; (b) a method for obtaining the extracellular membrane vesicle or the virus in the sample; (c) a method for removing the extracellular membrane vesicle or the virus in the sample; (d) a method for detecting the extracellular membrane vesicle or the virus in the sample; (e) a kit for capturing the extracellular membrane vesicle or the virus, comprising the Tim carrier; and f) a kit for capturing the extracellular membrane vesicle or the virus, comprising a reagent containing the Tim protein and a reagent containing the carrier.

Disclosed is an adapted Madin-Darby canine kidney cell line capable of suspension culture in the absence of serum, and a chemically-defined medium for culture of the adapted MDCK cell line. Further disclosed are culture methods for growing the adapted MDCK cell line and methods for producing a vaccine from the adapted MDCK cell line grown in the chemically-defined medium.