It's looking like we will have one empty spot in our little flock. I am considering whether to add an older pullet or hen either this fall before it gets too cold or next spring (realistically it would be next spring). I'd be open to an older hen whose family is rehoming because of decreased laying or what have you. But I am also considering not adding but just not having a full little flock. Really still in the exploring phase. One of my big concerns is whether I can find a bird that has already been vaccinated for Mereks. My other 4 have been and I don't want to introduce a bird which hasn't. I understand the whole quarantine and introduction to the flock issue. But my big question is - can an older pullet or hen be vaccinated? And if someone tells me that their birds have been vaccinated - would there be a harm in revaccinating??? Other question after I get the important Mereks question out of the way.... I know the recommendation is to try to introduce another chicken with a pal (so at least two at a time) so they have a buddy. How hard and fast is this recommendation? Since I could only add 1 then if it is destined not to work because there's not room for a "pal" I would just not do it. Would appreciate thoughts on either of these questions.