XK and influenza: Various antigenic epitopes are particularly effective, owing to their ability to induce a wide spectrum of immune responses in the host.75,76 Insect or mammalian cells can easily create virus-like particles (VLP) vaccines incorporating influenza hemagglutinin (HA) and neuraminidase (NA) antigens by expressing HA and NA proteins together with a viral core protein, such as influenza M1.