I've had vaxed people as house guests many times and nothing strange happened.

But recently, the day after they left I had a strange tickle in my nose and went through about half a box of tissues as my body tried to clear whatever it was.

This was very odd. Not like allergies to cat hair or pollen. It was more like I had a feather up my nose and my body was trying super hard to get rid of it. It went on for about 2 hours.

I don't know if it was from the visitors. It was just really strange.