Hello, I have 18 chickens that are about 1 year old, 3 bantam chicks that are 2 weeks old, and 14 eggs in the bator. I havent had any problems (knock on wood) with Marek's but I am thinking about vaccination. I dont know if my 18 1yr old's have ever been vaccinated, I didnt get them from a hatchery I got them from a farmer about an hour away from me. Also, the 3 bantam chicks I got from TSC 2 weeks ago and never asked them (stupid me) I have 3 questions: 1. Should I vaccinate the chickens that I already have? 2. If they were already vaccinated would it hurt them to do it again? 3. Can I buy the vaccine at a store or does a vet have to do it?