lol, cheetah!
I vaccinated chicks I from the hatchery, and did so for more than a decade. very very rarely lost a chick.
Now I have had unvaccinated chicks for the past two springs, and now I have mareks in the flock. And I am looking at losing 40% or more of my current flock, to miserable deaths if I don't cull early enough.
vaccinating is a tough issue. someone told me, and I didn't verify whether this was so or not, that the fda says backyward flocks shouldn't be vaccinated against mareks. It is a mutating virus. the vaccine isn't foolproof - the virus mutates, and I've seen estimates that maybe 10% have errors in admintering the vaccine - it has to be kept cold, etc.
but, having watched my sweet little cream legbar rooster get paralysis from mareks,....would I do it differently if I could? absolutely.
To add to the complexity of the issue - broodies =unvaccinated chicks because the vaccine isn't set up for small flocks, and the one available isn't so great even if you went to the time and expense and effort of trying to do it right. And getting chicks from small breeders, ditto. SO if you are going to breed, you will likely have unvaccinated chicks. But, if you are getting from a hatchery.....why not?
I haven't ever gotten a flu shot. I would bet my reasons for not getting them would be the same as some of the reasons behind others on this thread who choose not to vaccinate when given the chance.