These VLPs contain the hemagglutinin ( HA ) , neuraminidase ( NA ) and matrix 1 ( M1 ) proteins found in the newly emerged H1N1 influenza strain . The size and structure of the VLPs are nearly identical to those of the novel H1N1 virus but the VLPs are not infectious as they lack the genes necessary for replication . Novavax has made purified influenza A ( H1N1 ) VLPs , which are being sent to scientists at the CDC and DMID for studies in animal models .