I have 18 chickens (15 hens, 3 roos) and I will be hatching some eggs from them this year. My flock was all vaccinated for Marek's by the hatchery when I got them. Does this immunity they received transfer to their babies? Or will I have to vaccinate the chicks? I will be hatching and brooding in the house. Sorry if this has been answered somewhere before, I've been searching and couldn't find this question answered.