Do vaccinated new chicks put unvaccinated chicks at risk?

[Amy Carter]

I have week old chicks who were not vaccinated for Mareks. I have chicks arriving in a week and since it's a larger number I was going to have them vaccinated for Marek's. I'm finding conflicting opinions. Some say the vaccinated chicks are vaccinated with the disease itself and that they can slough it off and put my existing chicks at risk. Some say that's ridiculous and the vaccine isnt made out of the disease itself. Please give me advice if you know for sure so I know whether to vaccinate next weeks chicks.
Thanks!

 

[Eggcessive]

I have both vaccinated and non-vaccinated chickens, and have never had a problem with Mareks. Mine are all 5-7 years old.

 

[Amy Carter]

I have both vaccinated and non-vaccinated chickens, and have never had a problem with Mareks. Mine are all 5-7 years old.

Thank you

 

[Eggcessive]

In this article you can find info on the vaccine not causing shedding of the virus:
https://www.backyardchickens.com/articles/the-great-big-giant-mareks-disease-faq.66077/

 

[Amy Carter]

In this article you can find info on the vaccine not causing shedding of the virus:
https://www.backyardchickens.com/articles/the-great-big-giant-mareks-disease-faq.66077/

I appreciate this soooooooooooooo much!!! Thank you!

 

[Nambroth]

That link should cover it, but if we are talking ONLY about the Marek's vaccine, the vaccinated chicks do not put the unvaccinated ones at risk. This is a myth! The reason this myth exists is that vaccinated chickens that are exposed to Marek's disease will still become infected, but the vaccine will hopefully help them build a strong immune system so that they don't die from it. They will, however, still shed Marek's virus IF they have been exposed. This makes them "silent carriers" in a way. Unvaccinated chickens can also do this, if they are exposed and manage to beat the disease and survive.

In a nutshell: Marek's vaccine can not, by itself, cause a vaccinated chicken to spread Marek's disease to other birds.

Best case scenario: None of your chickens are ever exposed to Marek's and all is well, horray!!

Worst case scenario: Your chickens are exposed to Marek's. The vaccinated chicks have a higher % of survival, and the unvaccinated chicks have a lower % of survival. All exposed chickens can shed the virus the rest of their lives even if they survive with no symptoms.

Please remember that according to all the literature available, it's important to completely isolate any new chicks for at least 3-4 weeks after vaccination (so their first 3-4 weeks of life) from any other chickens or areas that chickens have been. This is to help give their immune systems time to "learn" the disease* from the vaccination and build up an immune response.

Hope this helps!

 

[Amy Carter]

That link should cover it, but if we are talking ONLY about the Marek's vaccine, the vaccinated chicks do not put the unvaccinated ones at risk. This is a myth! The reason this myth exists is that vaccinated chickens that are exposed to Marek's disease will still become infected, but the vaccine will hopefully help them build a strong immune system so that they don't die from it. They will, however, still shed Marek's virus IF they have been exposed. This makes them "silent carriers" in a way. Unvaccinated chickens can also do this, if they are exposed and manage to beat the disease and survive.

In a nutshell: Marek's vaccine can not, by itself, cause a vaccinated chicken to spread Marek's disease to other birds.

Best case scenario: None of your chickens are ever exposed to Marek's and all is well, horray!!

Worst case scenario: Your chickens are exposed to Marek's. The vaccinated chicks have a higher % of survival, and the unvaccinated chicks have a lower % of survival. All exposed chickens can shed the virus the rest of their lives even if they survive with no symptoms.

Please remember that according to all the literature available, it's important to completely isolate any new chicks for at least 3-4 weeks after vaccination (so their first 3-4 weeks of life) from any other chickens or areas that chickens have been. This is to help give their immune systems time to "learn" the disease* from the vaccination and build up an immune response.

Hope this helps!

It all makes so much more sense now! Thank you Now I can go back to the simple pleasures of impatiently waiting for my new chicks

 

[Nambroth]

Best wishes for your new chicks!