Poor Vampire-chan has all the bad luck.

Always check for allergies.

Unless it's Gluten, you need to check if they actually have Celiac disease or are just a colossal dumbarse.

I hate loving Vampire-chan's misery.

Come to think of it, there's not many series with weakass vampires. Weren't vampires originally hard to find, not hard to fight?

Not even that. The "original" vampires were corpses that were dug up and thought to have been feeding due to bloat, along with apparent "growth" of the hair and fingernails, IIRC.