Mine are Marans x legbar and Ameraucana. I think the Marans do not have any resistance at all (At least mine don't). My Wheaten crosses are also sick as well as the ones I gave to a neighbor.I have not had mareks problems with my OEs, they are Penedesenca x Cream Legbar. I have new OEs that are Penedesenca x Arakansas Blue egg layers. So far they have been fine with mareks resistance.