Question about Vaccinated chicks

[SilkiesAndSuch]

Alright. I have two sets of silkie chicks. The two sets are slightly different ages, with one set being about 4.5 weeks old and the other set around 6-7 weeks old. The younger set is from cackle hatchery and is vaccinated for Mareks. The older set is from Sunshine Silkies, a local breeder of show quality silkies and is not vaccinated. Is it alright to mix these two sets of birds? Will the vaccinated birds contaminate the non-vaccinated chicks? I would really like to slowly integrate the two sets, but don't want to cause the older set to get sick......They cost me soooo much more than the cackle hatchery chicks.

 

[Chickielady]

I have some that are vaccinated and some that are not, and no problem.
If Mareks' ever spread out here, God help us all, but half my flock would then be OK, and survive.
The unvaccinated ones would fall ill.
Like as if some of us humans had a flu shot, and some of did not.