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.

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 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 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.

New influenza donor strains for the production of reassortant influenza B viruses are provided.

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.

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

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.