Do Marek's vaccinated birds automatically become carriers?

[threehorses]

Quote:
They won't shed turkey virus because they don't get the disease. They only have a reaction to a certain protein or part of a DNA string that the two diseases share.

They only shed if they get chicken virus actively is my understanding.

 

[FarmerDenise]

FYI, we had around twenty chicks last year. More than 1/2 were vaccinated for mareks, some at the hatchery, some by me and some by a vet. I still lost most of my birds to mareks ( I had necropsies done to find out). In my case, it made no difference whether the chicken was vaccinated or not. Some of my survivors were vaccinated and some were not.
This year I did not bother to vaccinate any of my homegrown chicks. The store bought ones came vaccinated. I'm keeping my fingers crossed that none of them will get marek's this year. Seems to work as well as vaccinating them.

 

[threehorses]

I had both, honestly. I don't recall ever having a case of Mareks in hatchery birds. I do recall having it in home grown - but that's anecdotal.

Any bird, even vaccinated, will have the vaccine fail if they're exposed strongly to the disease. It's the medium to low exposures that we want to eliminate the signs of disease (which are what kill the bird, not the disease itself): the tumors and paralysis. So I still recommend it and will be vaccinating any hatchlings here from this point forward to lower the possible number of cases. Particularly because of the tumors - I can't know which birds have that, and unknown reasons for deaths make me crazy.