Improved methods for the production of reassortant influenza viruses are provided.

The invention relates to an immunogenic composition comprising influenza virus antigens derived from at least 5 influenza virus strains and one or more compounds of formula (I) or physiologically acceptable salts or esters thereof: wherein: R.sub.1 represents hydrogen or C.sub.1-6 alkyl; R.sub.2 represents C.sub.1-6 alkyl; and R.sub.3 represents C.sub.1-6 alkyl. The invention also relates to methods of preparing the immunogenic composition, to pharmaceutical and vaccine compositions comprising the immunogenic composition and to use of the immunogenic, pharmaceutical and vaccine compositions for preventing influenza virus infection.

The invention provides various reverse genetics systems for producing segmented RNA viruses, wherein the systems do not require bacteria for propagation of all of their expression constructs.

Disclosed herein are nanoparticles suitable for use in vaccines. The nanoparticles present antigens from pathogens surrounded to and associated with a detergent core resulting in enhanced stability and good immunogenicity. Dosages, formulations, and methods for preparing the vaccines and nanoparticles are also disclosed.

The present invention provides a vaccine containing virus-like particles derived from virus particles having an envelope, in which a lipid-component content of the virus-like particles is reduced relative to a lipid-component content of the virus particles.

Disclosed herein are methods for increasing protein yield and cellular productivity. Chemical agents facilitate host cell production of biological molecules to increase product yield.

The present invention provides a vaccine containing virus-like particles derived from virus particles having an envelope, in which a lipid-component content of the virus-like particles is reduced relative to a lipid-component content of the virus particles.

The invention relates to generic methods for the detection and quantification of influenza viruses. These may uses a reverse transcription (RT-PCR) real time (q-PCR) assay which amplifies a conserved region within influenza A or B strains. The assays allow the quantification of influenza virus RNA molecules or whole virus particles, irrespective of the particular virus strain (e.g. human, avian, swine flu). The methods are particularly applicable as diagnostic assays or in the monitoring of vaccine production processes.

The present invention is directed to methods of purifying viral proteins for use in vaccine compositions. The method includes a capture step and a polish step. The capture step includes passing a solution containing a protein over a hydrophobic interaction chromatography column and eluting a crude protein eluate from the column. The polish step includes passing the crude protein eluate over a ligand affinity chromatography column and recovering a first flow through intermediate, passing the first flow through intermediate over an anion exchange chromatography column and recovering a second flow through intermediate, and passing the second flow through intermediate over another ligand affinity chromatography column and recovering a purified protein eluate. The present invention also provides a purified protein having a hydrophobic membrane domain that is produced by a baculovirus expression system in cultured insect cells, wherein the purified protein has a purity of greater than 85%.

Currently, the steps performed prior to release of influenza strains to vaccine manufacturers involve passaging influenza virus through eggs. The invention aims to provide procedures useful in manufacturing influenza vaccines, in which the use of eggs is reduced, and preferably is avoided altogether. For instance, rather than use chicken eggs for influenza vaccine isolation, MDCK cells (Madin Darby canine kidney cells) may be used e.g. growing in suspension, growing in a serum-free medium, growing in a protein-free medium, being non-tumorigenic, grown in the absence of an overlay medium, etc.