very interesting article about Marek's vaccine

I found an article in the Internet about Marek's vaccine that has completely blown my mind.

http://www.pbs.org/newshour/updates/tthis-chicken-vaccine-makes-virus-dangerous/

I have been a chicken keeper for almost 5 years and every time I get chicks I have had them vaccinated for Mareks. My first encounter with the virus was about three years ago when one of my ameraucana pullets got ill and died after taking her to the vet. My vet said she had Mareks, I had her tested for it, the results came back positive.I have however always wondered if the test came back positive because she had been vaccinated and obviously had the virus' antibodies. My second encounter was about a month ago when my very young rooster had a bump in his head that came up over night. I thought it was a hematoma but after a week and a half it was still there. I found him dead in the run one afternoon. He had slowed down a bit in the last 2 days of his life but he was still moving around. I did not have him tested for Marek's and he was vaccinated. I cannot say with certainty that he died of Mareks.

I would like to hear opinions about this article. It is a complete different approach of what I have read so far and now I wonder if I should continue to vaccinate my chicks ????

So, I didn't read the whole article because I'm at work and I don't know if it mentioned this, but the vaccine is made with a turkey virus, not real Marek's, which is why it is 'leaky' as the article said. The virus they use is close enough to give immunity to Marek's symptoms (most of the time) but does not prevent the bird from actually getting Marek's. So if they found Marek's antibodies in your hen, she really did have Marek's, it wasn't the vaccine making them show up.

As for your rooster, I couldn't say if his death was Marek's related. Could have just been a bump to the head that caused the hematoma and a brain bleed. To know for sure you would have had to have sent him for a necropsy.

If your hen really did have Marek's, then yes, you should vaccinate all other chicks you bring in because at this point you'd have to consider your flock infected and any new birds you get that aren't vaccinated would likely contract it and suffer from it and possibly die. Or you could opt not to vaccinate and try instead to breed for immunity; there is a thread on these forums about that somewhere.

Thank you Pyxis for your reply. I only buy one day old chicks every year and have them vaccinated, I do not breed even though I have a rooster. I will continue to vaccinate my chicks

aldarita said:

Thank you Pyxis for your reply. I only buy one day old chicks every year and have them vaccinated, I do not breed even though I have a rooster. I will continue to vaccinate my chicks

Click to expand...

And if you need to rehome a bird for some reason, you should do so with full disclosure that the flock has had Marek's exposure.

Of course, that is the responsibility that every chicken owner must have. Every member of my flock stays in my yard until they die, even then, they get cremated by me or my vet (depending on where they are when they die).