Pro tip: If you know someone has issues with their immune system, tell them if you get sick. If you have plans, let them know you’re sick (yes, even if you’re “mostly over it”). If they choose to risk it, then at least it’s their choice, and they can take extra steps to avoid catching your bug.
If they ask to reschedule, or do go but refuse to touch you or get to close, don’t get angry. Don’t be offended. They’re literally just trying to look out for their health.
Even if it’s a scratchy throat, or you feel a little stuffed up, and you’re not “really sick”, still say something.