Marek’s vaccine dilemma

[ZeiaZeia]

Chicken vaccines Contain turkey mareks.

Plus considering my flock is a mixture of vaccinated and unvaccinated, I would fully expect to be losing birds if the vaccinated ones spread mareks

This is why Marek’s vaccine is called a “leaky” vaccine it is well known and documented to spread Marek’s into the environment but not all birds succumb to it generally it’s only juveniles under 20 weeks of age.

 

[KRack]

If your chicken had Marek's, then the rest of your chickens likely do/did too. They're vaccinated, so it's hiding their symptoms. But that doesn't mean they're not spreading it rapid fire. It's a leaky vaccine that causes shedding. I'm pretty certain Marek's is everywhere, it's just that most people vaccinate and are lucky enough not to notice. My vet seems to be of the opinion that vaccinated birds only shed once they've come in to contact with the live virus and have to fight it.

I have had a suspected Marek's case in my flock too. With a vaccinated bird. I plan on letting one of my chickens hatch a clutch of eggs and not vaccinating them, and seeing what happens. I've read a lot about breeding for resistance and live around a lot of Amish that don't vaccinate their birds and have very robust flocks.

So to answer your question, based on what I've read and my vet has told me, your vaccinated chickens will likely spread Marek's if they've been exposed to it.

 

[Henhouse Harlot]

https://www.pbs.org/newshour/science/tthis-chicken-vaccine-makes-virus-dangerous