Not a VET! However, long years of experience, isolated farm, long before computers and internet, then longtime search and research-- lots of misinformation, lots of guesses, and lots of good information, to convince one that while much is known about Marek's, much is still to be discovered. Experience with RECORDS, has several local Vets sending questions to me (might help, might NOT.) We have no local hatcheries any more (and before Marek's was a problem) but Feed Stores carry them, and it soon will be question time--(a month or 2 for cockerels--4-5 months, just before first laying for pullets is normal, but of course can vary.) Even if you can order vaccinated chicks, if they arrive with the non vaccinated--they may be exposed already and cannot have the 2 weeks to develop immunity.
Had chickens for YEARS, with NO MAREK's or anything similar. It first arrived with lovely birds from friend in Alabama. Hen went down on one leg shortly after arrival--then wing on same side, then DOWN and died in several more days??????no idea what it was. Spoke with the breeder, who was sorry--he was breeding for "immunity to Marek's! Of course it was classical symptom--now, easily spotted!!!!!
Breeding for immunity IS possible with most breeds of poultry. TAKES YEARS--AND after a long time with birds not showing any symptoms, how do you really know if all your birds are immune?? FEW Vets do the blood work. ANd some infected birds do recover AND ARE CARRIERS OF THE VIRUS for the rest of their lives--and can carry infection to any birds hatched or acquired later-=-years later. Marek's is a LONG LIVED VIRUS. How long? We do not really know!! The best philosophy is "ONCE YOU HAVE IT, YOU CAN ALWAYS HAVE IT!!!!!
After not having birds with symtoms, for several years, sold some really nice birds, shipped, AND a month or so later, the buyer wrote to say that they were sure that one pullet was going down with MAREK'S . How could I have been so fortunate to have sold the birds to a family that vaccinated all their birds.
WHile I had read and learned (our local Vets do not really do chickens , but good Vet friend did send a bird that I had purchased, had been vaccinated, quarantined after arrival here, but died 10 days after receiving him, for necropsy. It was Marek's--so we do know that while vaccination is IMPORTANT, it may not be 100% and stress can break the immunity--same as vaccines for people, With this experience--NEXT HATCH, I started vaccinating and have for 14 years, every chick within or closest possible, to 24 hours of hatch. Have learned to schedule hens to hatch for same day , to save vaccine as it does not keep after mixing! That infected pullet that I had sold? I hatched, vaccinated, raised the same variety bantams and later sent the family, not just one, but TWO pullets as replacement. Marek's is not carried in the eggs and recovered birds can produce lovely fertile eggs. Exposure is after hatch!
Since it may take 2 weeks for a vaccinated chick to develop immunity, it is with faith that chicks are started in their own "isolated" pens, and hope that they are in no way exposed to the virus (which can still be anyplace former infected chickens have lived --and their own mothering hen, even a dear old one--"could have some dander with the virus??????) 2 weeks!
It is all we can do--but DO IT. And now, I will not even purchase a vaccinated bird. Time to let TIME kill the virus that may still be lurking on my premises. AND the virus is continually mutating--is the vaccine broad spectrum for present and newest forms? We must do what we can do--worth the efforts, of course, my bantams are part of the family farm--and deserve no less than my children did!!
You CANNOT give a bird Marek's by vaccinating. The vaccine is not made from Marek's Disease!! It is made from aTurkey Herpes Virus, which causes chickens to DEVELOP an immunity to MAREK's. May sound strange, but that's the way it is!
GOOD LUCK
And of those who deny Marek's in many ways, I respect your point of view--I live by my long time experiences--and I well know that the book is not closed on Marek's--lots yet to learn.....