Lifeburst by Jack Williamson to lovecraftain but fits into to Cosmic horror category.I suppose Lovecraft isn't subtle enough for you? Or not science fiction enough?
Edit: I once read a novel about a "horror" type vampire on a starship. He met a "psychic vampire" type entity and mentioned that he had never met a vampire before.
I wasn't crazy about the book and don't remember any more of it.