Can vampires sustain themselves on alien blood? Just imagining a brood of vampires conquering Earth and then setting their eyes to the galaxy. Like they have vampire scientists who find ways to let them enter sunlight and enjoy Italian food once more.

People suggesting you’d have to kill for blood haven’t seen true blood. IIRC the vampires in that book/show found a way to coexist with humans because human nations created artificial blood (that you could buy like soda at a convenience store etc)

Edit a whole bunch of other stuff happened, but that’s one aspect from that setting