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