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 relates to the microbial immunogens engineered to bear -gal epitope(s) for induction of potent humoral and cellular immune responses when administered to subjects having anti-Gal antibodies. In one embodiment, the present invention provides compositions and methods for propagating influenza virus in human, ape, Old World monkey or bird cells that have been engineered to express an 1,3galactosyltransferase ( 1,3GT) gene to produce virions bearing hemagglutinin molecules containing -gal epitopes, to increase the immunogenicity of the influenza virus. In another embodiment, the present invention provides fusion proteins between influenza virus hemagglutinin and a microbial peptide or protein of interest, and enzymatic processing of this fusion protein to carry -gal epitopes, to increase the immunogenicity of the microbial peptide or protein of interest.

The present invention relates to the microbial immunogens engineered to bear -gal epitope(s) for induction of potent humoral and cellular immune responses when administered to subjects having anti-Gal antibodies. In one embodiment, the present invention provides compositions and methods for propagating influenza virus in human, ape, Old World monkey or bird cells that have been engineered to express an 1,3galactosyltransferase ( 1,3GT) gene to produce virions bearing hemagglutinin molecules containing -gal epitopes, to increase the immunogenicity of the influenza virus. In another embodiment, the present invention provides fusion proteins between influenza virus hemagglutinin and a microbial peptide or protein of interest, and enzymatic processing of this fusion protein to carry -gal epitopes, to increase the immunogenicity of the microbial peptide or protein of interest.

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

This application relates to modified influenza B hemagglutinin polypeptides and nucleic acids, such as messenger ribonucleic acids (mRNAs), encoding the same, as well as compositions comprising the same, vaccines comprising the same, and methods of using the same, such as in the prevention and/or treatment of diseases or conditions caused by influenza B viruses.