Eugenicists want to advance the human race by optimizing the herd like cattle breeders do - cull the weak, select the "best" ones for breeding, and optimize by gene manipulation. Traditionally, eugenicists have used infertility and abortion instead of mass murder, because they believe they are morally superior. DNA manipulation is done by adenoviruses, they cure hereditary diseases in children with manipulated adenoviruses for a decade now. The adenoviruses in the vaccines don't have the payload needed to manipulate DNA (yet), they are just a huge trial of the delivery vector.