 The influenza strain composition of the Quadrivalent VLP Vaccine used in this study includes 2 influenza A virus strains ACalifornia72009 H1N1 and ASwitzerland97152932013 H3N2 and 2 influenza B virus strains BPhuket30732013 Yamagata lineage and BBrisbane602008 Victoria lineage, based on the 2015-2016 recommended World Health Organization WHO strains for vaccination in the Northern hemisphere. 