A method for synthesizing influenza virus-like particles (VLPs) within a plant or a portion of a plantis provided. The method involves expression of a novel influenzaHA protein in plants and its purification The inventionis also directed towards a VLP comprising influenzaHA protein and plants lipids. The invention is also directedto a nucleic acid encoding improved influenza HA as wellas vectors. The VLPs may be used to formulate influenzavaccines, or may be used to enrich existing vaccines.
