Can a 12 week old chicken (now 22 weeks) who's been vaccinated for Marek's at a day old contract Marek's if they were around a chicken who had it? She was around her for for about 8 weeks before the other one died. We thought she'd been vaccinated, but then found out the breeder had a problem and actually wasn't. The one left (22 weeks old) was from a different breeder and seems very healthy. Just wondered if she could still contract it or be a carrier if she'd been vaccinated in the begining. Thanks!