Thanks so much for getting back to me! I really appreciate it. So yours are right next to each other, but haven't been mixed in yet? Mine are now 8 weeks old and haven't seen the older hens. I've been careful about wearing different shoes in each coop area and washing my hands thoroughly between coop visits. Honestly, Mareks is so contagious that this might be overkill since the chickens are 100 yards down the hill from the chicks and I'm sure their dander is flying around.
I LOVE your idea about getting directions from hatcheries on how to care for Mareks vaccinated chicks. The advice here on BYC is excellent and appreciated, but there's also so much conflicting information elsewhere on the Internet. Please keep me updated on your chicks and introduction to your established flock! I'd love to hear how integration goes and if the vaccine works. I'll let you know how things go here when we introduce the new chicks.