vangela- sory to hear about your chick seems at this point euthing him/her might be your best option.
http://www.addl.purdue.edu/newsletters/2005/Spring/mareks.htm
new site i found to read up on mereks, hopefully it is accurate, it seems a good read to me.
from my findings (hopefully correct)...
it is exceptionally difficult to learn about this disease as every site says something different, i have read that for sure it can be passed from parent through egg to chick on some sites, and on others that it cant be.
my vet told me it only lives for 10 days once birds are removed from...
from my reading the vaccine is not effective unless properly quarantined/administered, which to me seems a clean room that you scrub up before going in to is neccesary, because if you bring dander/poo from a carrier (that is how it is transferred) near the vaccinated chicks less than 10 days...