A method for synthesizing influenza virus-like particles (VLPs) within a plant or a portion of a plant is provided. The method involves expression of influenza HA in plants and the purification by size exclusion chromatography. The invention is also directed towards a VLP comprising influenza HA protein and plant lipids. The invention is also directed to a nucleic acid encoding influenza HA as well as vectors. The VLPs may be used to formulate influenza vaccines, or may be used to enrich existing vaccines.

Provided is a seasonal influenza vaccine having a higher efficacy than a split vaccine. A seasonal influenza vaccine which induces virus-specific antibodies in the nasal mucosa, comprises inactivated whole influenza virus particles as an active ingredient, and is to be administered intradermally at dose per administration of 15 μg HA or more per strain as antigen.

This invention discloses a method of increasing production of virus-like particles comprising expressing an avian influenza matrix protein. The invention also comprises methods of making and using said VLPs.

An isolated expression enhancer active in a plant, portion of a plant or plant cell, the expression enhancer is provided. The isolated expression enhancer may be selected from the group consisting of nbEPI42 (SEQ ID NO:1); nbSNS46 (SEQ ID NO:2); nbCSY65 (SEQ ID NO:3); nbHEL40 (SEQ ID NO:4); and nbSEP44 (SEQ ID NO:5). Methods for using the isolated expression enhancer are also provided.

A method of producing a virus like particle (VLP) in a plant comprising modified H3 hemagglutinin is provided. The method comprises introducing a nucleic acid comprising a regulatory region active in the plant and operatively linked to a nucleotide sequence encoding a modified influenza hemagglutinin (HA) protein into the plant, or portion of the plant, the modified HA protein comprises a modified proteolytic loop. Followed by incubating the plant or portion of the plant under conditions that permit the expression of the nucleic acids, thereby producing the VLP. The modified proteolytic loop may comprise one or more protease cleavage sites exhibiting reduced or abolished cleavage by a protease. Also described is a virus like particle (VLP) produced by the method, and plants expressing the VLP. The virus like particle (VLP) may comprise plant-specific N-glycans, or modified N-glycans.

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.

Provided is a method for efficiently proliferating an influenza virus serving as a material for vaccine in a host.

A method for proliferating an influenza virus in a host, comprising a step of inhibiting transfer of Bax in a host cell to the inner mitochondrial membrane.

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

A method for synthesizing influenza virus-like particles (VLPs) within a plant or a portion of a plant is provided. The method involves expression of influenza HA in plants and the purification by size exclusion chromatography. The invention is also directed towards a VLP comprising influenza HA protein and plant lipids. The invention is also directed to a nucleic acid encoding influenza HA as well as vectors. The VLPs may be used to formulate influenza vaccines, or may be used to enrich existing vaccines.

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.