Hi all, Next Spring I plan on hatching my own eggs. I do not want to vaccinate. I currently have 5 birds(8 months old) that came from a hatchery and are Marek's vaccinated. What are the odds that the original birds can 'shed' Marek's disease to my new birds? Can it happen? Is it common? Is it a definite? Found this: I think this answers my question... I hope this is correct. Anywone? I understand your and your poultry pal's concerns but you are right in your thinking about Marek's disease. Marek's disease virus is everywhere. In fact, the vaccination of poultry for Marek's disease is a race to see which virus is going to win in the bird.....the vaccine virus or the disease causing virus. While it is true that Marek's disease vaccinated birds are infected with the vaccine virus for life, I am not aware of them shedding the vaccine virus. The good news is that the vaccine viruses do not cause disease so your chickens are safe and not "Typhoid Marys." The other vaccines used in poultry do not cause "Typhoid Marys" except for almost all vaccines used to protect against Infectious Laryngotracheitis. Chickens vaccinated with those vaccines can shed the vaccine virus and the vaccine virus will make non-vaccinated chickens sick. As for vaccinating your chickens for other diseases, I only recommend vaccinating chickens against diseases you have had or that are in your area. In most cases, that only includes fowl pox. Please note that chicken pox is a human disease and not a chicken disease. The virus that causes chicken pox in humans does not cause disease in chickens nor do humans get it from chickens. Hope this helps, R. M. Fulton, D.V.M., Ph.D.