In a case like this I don't think "taking sides" really makes sense as a reader. The vampires need human blood to survive so ofc they're going to take that blood by force if necessary because the alternative is just starving to death. On the other hand, humans don't usually like having their blood taken by force so they will try to stop the vampires.
We're meant to sympathize more with the vampires as this story focuses on them, but both sides are just fighting for their own survival so neither is really "in the wrong". You wouldn't call a lion evil for hunting a gazelle, but the gazelle might
Ideally, of course, the humans would donate blood to the vampires and everyone would live in harmony, but that seems unlikely; humans wouldn't be eager to offer charity to the "monsters" that have been hunting them and vampires wouldn't be happy about living on the charity (and thus, being functionally subservient to) the humans that were once their prey