[Private: Michelle/Caroline]
I haven't had a scratch. I'm here to help out, and to help defend the infirmary if the dogs show up. If feeding you means you're a) no longer a patient, and b) can help fight if necessary, it's a win-win.
Also, I don't think you fully grasp what being immortal means. Even if you drained me, I'd be up and around very quickly (albeit thirsty).