Merek's is what chicks are vaccinated for, I forgot about that earlier. It's contracted from other birds via dander and not transferred to humans. I hatch and raise my own birds so they are not vaccinated. Never had Merek's disease enter the flock. It's probably a good insurance to vaccinate if you've a large operation and high quality stock as there is no cure for Merek's once it's in a flock the flock must be closed (no birds in or out) or it will spread to other flocks. You'd hear if Merek's is your area on the news. Most euthanize a flock with Merek's, sanitize everything and start again.