I don’t know how long it stays alive. Did you know it is actually Turkey Marek’s virus they use in chickens? It’s not Chicken Marek’s virus. And it does not stop the chicken from catching or even spreading chicken Marek’s. It stops the lesions from growing that cause the damage. If you are worried about it spreading to your chickens, stop worrying. I seriously doubt if it would, but if it did, that would be a good thing as long as you don’t have turkeys.
As Ridgerunner says, the most prevelent form of vaccine is the turkey marek's virus. I usually takes 7 - 14 days for this to do it's job and leave the chick, although it can take longer in some. Chickens cannot get turkey Marek's, same a humans were vaccinated with cow pox to keep them from getting small pox. There are some hatcheries that will vaccinate with all three forms of Marek's vaccine. This is the way to go even though there is a 4 week waiting period after given before these chicks can be around other birds. Turkeys are not affected by the turkey Marek's the way chickens are. There is very low mortality among turkeys. As for it stopping the chicks from getting Marek's...in a perfect world, that's just exactly what it's supposed to do. Unfortunately, there are mutated forms of Marek's out there now and none of the vaccines seem to work well on the more virulent forms that keep popping up. I highly recommend that everyone vaccinate their new chicks and practise the best biosecurity possible. Will it stop it from hitting your flock? Maybe, but not always. It is still the best possible defence you can have.
