I have 1 roo and 3 hens that are 2 yrs old and I heard somewhere on here that if you get chicks you order vaccinated they will give it to chickens you already have. Is this so? I order chicks from MM and got them vaccinated for both Mareks and the other and they are supposed to be here the week of 3/26(next week). My roo and hens have never been vacinated and are as healthy as can be. Does anyone know about this or where I can get more information.