Just lost my five week old chick to a leg paralysis that I suspect was Mareks. I am waiting for lab results to confirm. Was a brutal thing to go through. Vaccinate your chicks. Mareks is brutal. The vaccination does not compromise organic status, does it? Can't think of a better way to spend a buck on a chick. Read some of those threads on the disease board. Mareks in not pretty and if there is a safe way to avoid, seems a no brainer.