I always got the job of cleaning out the growth around the tree stands.
Seems i was the only one that both of these plants did not bother.
Must have been from growing up in the swamps of MS.
Man i miss those days.
You don't build up an immunity to oak or ivy. You just have it...for now. Overexposure, though, will kill your immunity and once it's gone, it's gone. Stay away from the stuff to preserve the immunity you have in case you need it.