The dark side here is a reference to the underside of the neuraminidase (NA) protein head. It's a conserved region of the virus as, while influenza is notorious for it's continuous mutations thanks to the segmented genome, a viral capsid and glycoproteins are always kept together during reassortment. So, if we can figure out how to make vaccines which target this conserved protein, it will function against most influenza strains, rather than having researchers make educated guesses as to which strains will be most prominent each flu season. Not as cool as start wars, but still super rad!!