Ok I have 9 hens and 2 roosters. All have been "vaccinated" when I purchased them from their feed stores. I bought them all from 3 different stores and they were all listed as already being vaccinated. Now I have 3 eggs setting under a broody hen. I am unsure if they will hatch yet or not, but if/when they do would I have to vaccinate for Mareks? Without know exactly what my others have been vaccinated for what would I know to vaccinate them for? Would Mareks be the only thing I would have to vaccinate them with?