Apparently they made a movie about this called Lifeforce but I’ve never seen it. It sounds like from reading reviews that the movie is way better than the book, so maybe you want to go watch the movie instead of reading this book?
There are some astronauts who find an alien ship that is full of what looks like corpses in suspended animation, and they start trying to study them. The bodies are humanoid but are obviously alien and seem to be dead. But then one of the astronauts tries to make out with one of them bodies and she comes to life, and somehow manages to steal his life force. This is a really common trope, and I am doubting that this story is the origin of it. When the alien manages to get away and starts killing people and sucking their life force, and maybe jumping bodies, a couple of scientists try to track down a guy who wrote a book on vampirism to get more information on how to stop the aliens (maybe) and end this scourge against humanity before the vampires take over the world, or something.
I think this book definitely shows its age in a lot of ways. I suppose you could say it’s philosophical about the nature of vampirism and things taking life force from others to survive, and some of the characters in the book seem to be trying to act “scientific” and all of that. Also it’s possible that someone would find this book sexy with its sort of necrophilia of people trying to make out with corpses. But I’ve read enough books like this so it just made me really want to roll my eyes. It’s possible if I had read it as an adolescent, I would have found it more interesting. Still, maybe I will go see that movie Lifeforce since it has a young Patrick Stewart in it.