An isolated protein comprising a VP1 amino acid sequence wherein one or more exposed loops within said VP1 has an insertion of an amino acid sequence from a virus protein other than VP1, and encoding nucleic acid, are provided. Typically, the virus protein other than VP1 is derived from an influenza virus and in particular, avian influenza virus. The isolated protein may have an insertion of amino acid sequence from a single protein or a plurality of proteins. Also provided are expression constructs, VLPs, pharmaceutical compositions, vaccines and methods of treatment that may be useful in the prophylactic and/or therapeutic treatment of any disease of viral origin, and in particular, influenza virus.
