Mixing Marek's Vaccinated Chicks with Non Vaccinated Chickens

[Chick CJ]

I'm not sure if this is the right place to post this question but someone just brought up a question on my local chicken group about mixing vaccinated and non vaccinated chickens. They said they thought the marek's vaccinated chicks were carrying the virus and could pass it on to the non vaccinated chickens. Is this true? It doesn't sound correct to me. Also, another person said they bought chicks that were supposedly vaccinated but one died and she had a necropsy done and it was riddled with marek's. She was thinking it was not vaccinated and she was lied to but I was thinking a vaccination may not always work. Anyone have any ideas on either of these issues?

 

[Mac in Wisco]

The vaccinated chickens can carry and transmit both the vaccine virus and the regular virus to non-vaccinated birds. The vaccine virus will not hurt the non-vaccinated birds, the regular virus will. It's in their best interest to vaccinate the non-vaccinated birds before mixing them with other birds.

As far as the one that died... The vaccine is not always successful. It could have been vaccinated poorly or it could have been exposed to the regular virus before the vaccine virus had built up in the chick's system. It is generally a struggle between the two viruses for dominance, sometimes the field virus can overwhelm the vaccine virus. Also, certain strains of Marek's can be particularly virulent and break the vaccine.

 

[Chick CJ]

Thank you. That is very clear and I can understand it!

 

[susancarol]

I called the vaccine company. They stated to vaccinate the non vaccinated ones but it would do no harm but be worthless. I belive now it was a mistake because one died within two days, and two died within two months. We are having a necropsy done on the recent deaths. The idea here is the vaccinate with the atenauted before the live virus gets them. So in summary, I believe that vaccinating older birds did more harm than good. I have heard this before. So they say a remedy is St. John's Wort and that it will cure this disease. I hope it is true.