"They come at you with a little needle full of a clear liquid, it stings like a bastard when they jab you, and it feels like somebody slugged you in the arm for a couple hours afterwards. And then you don't get hyperplague. I've never had a bulk vaccination, though, so that might be different." He declines to contribute the mental image of about fifteen hypodermic needles sticking out of Bella's arm, suspecting that it would be unhelpful.