First aired: 2008
This anime was based loosely on the Kurt Wimmer film Ultraviolet. Changes included an interplanetary aspect, and the idea that the hemophages, or phages, were people infected by a virus that developed naturally whereas the original film made it clear that the virus was engineered to create bio-warriors.
That still is within the story vaguely because, as well as people infected with the ordinary phage virus, our protagonist 044 (Romi Paku) is a clone created to act as a government super-agent and specifically infected with a super strain of the virus that gives her enhanced physical skills but has created a finite lifespan (think incept dates for the replicants in Bladerunner). At the end of the anime there is also the mention of a secret – that might hint that it was a created virus.
This is not the best anime I have come across and, as I said, the vampire aspect is excruciatingly underplayed. However the story was compelling and I think the anime as a whole deserves 6 out of 10.
The imdb page is here.