Can you mix mareks vaccinated and unvaccinated chicks?

[-Bella Cataline-]

I have six vaccinated chicks at three weeks old, and I am hoping to include one chick that's unvaccinated. Would that work?

 

[CaliforniaMountainChicks]

My flock is a mixture of vaccinated and unvaccinated and all is well!

 

[Sussex19]

As long as don't actually have Mareks in your flock, then it doesn't matter at all. The vaccinated ones don't have the disease, and won't give anything to the unvaccinated one.

However, if you were in a position where you do have MD in your flock, then what could happen is the vaccinated chicks will be more immune, so won't show symptoms, but could be passing on a lot more of the disease, and the unvaccinated chick might die.
But vaccinations aren't 100% effective anyway.