I have a small flock - 1 roo, 1 drake, 4 hens - and am adding to it this spring, of course! My existing flock has not been vaccinated for Marek's, and is and has been healthy - no signs of any problems. When I ordered my new chicks I decided to get them vaccinated for Marek's (live in the country, free-ranging, etc.). When I integrate the chicks (3-4 months down the road) into my flock, will it expose my unvaccinated flock to the disease? If so, can I vaccinate my adult birds before integration? Sorry if this seems foolish, but I've read just enough to be confused. Thanks!