Lets Talk about Mareks

[Eggs_With_Legs]

Thank you I have read through the second article but hadn't seen the newer post. I am hearing locally from other poultry providers that the agricultural boards are actually recommending now that everyone gets the vaccine for their birds but I also hear from others about birds that end up contracting a much more deadly version or mareks because there are vaccinated birds and unvaccinated together.

Wow, I've never heard of that! Sounds scary, I'm going to have to look into it.
I read an article you wrote about breeding birds and that makes me think because you've had no problems over the past years, and I'm assuming you'd want naturally resistant birds, you might want to hold off on vaccines. But, that being said, if this theory of unvaccinated fowl being with vaccinated may cause a different form of Mareks, I'd either cull the four and vaccinate, or not vaccinate the new ones.
I think it all just boils down to your best guess and what makes you feel more comfortable.

 

[ChocolateMouse]

Vaccinated VS unvaccinated birds together don't cause the virus. The virus causes the virus. The vaccine just keeps infected chickens alive.

There are light strains and hot strains of the virus. The light strain "only" kills at least half of all your birds. The hot strain kills all of them. They're both highly contagious and nearly impossible to breed for immunity or remove from the environment.

If your chickens get the hot virus strain;
By not vaccinating your chickens you stop the spread of the "hot" strain of the virus.... Because all of your chickens die so they can't spread it anymore. Because they're dead. This gives you a chance via quarantining unvacced birds to potentially prevent the virus in your flock.
By vaccinating your chicks, you sort of let the hot virus strain keep spreading because the chicks don't just die to the virus before they can't spread it. Then they have no symptoms but keep spreading the virus.

If you get the light strain of the virus in chicks, chances are good it won't kill them until they're in your flock unless you have a LONG quarantine period (upwards of 32 weeks but at least 10). If they have it and go into your flock then half your chickens are dead if they're unvacced no matter what you do cause it lingers and takes longer to kill the chicks and by the time they're dying they probably all have it. If you get the light strain and they're vacced they all have it, they're deadly to unvacced birds, but they all live.
The hot strain DID develop in response to the vaccine. The vaccine still works against the hot strain of the virus.

Also there are two vaccine options. One is more effective than the other.

If your chicks are vaccinated and never exposed to the virus it doesn't matter if they are mixed with unvacced birds or not. Nobody is sick or carrying the virus so it doesn't matter.

If you're keeping chickens as pets you may want to consider vaccinating to help keep them alive.
If you want to stop the spread of the disease you may want to not vaccinate, cull heavily for good health, and send suspicious deaths to a necropsy lab to keep tabs on if the disease shows up in your flock.
If you're breeding for more than yourself you may want to be unvacced so other people can rely on knowing your flock is Mareks free.
If you get the disease you have to be prepared to close your flock or go chickenless for years whether you're vaccinated or not.

 

[LilyD]

Wow, I've never heard of that! Sounds scary, I'm going to have to look into it.
I read an article you wrote about breeding birds and that makes me think because you've had no problems over the past years, and I'm assuming you'd want naturally resistant birds, you might want to hold off on vaccines. But, that being said, if this theory of unvaccinated fowl being with vaccinated may cause a different form of Mareks, I'd either cull the four and vaccinate, or not vaccinate the new ones.
I think it all just boils down to your best guess and what makes you feel more comfortable.

I am still slowly working towards that my ideal would be to eventually have a closed flock of Orps that I can breed and hatch eggs from and keep the roosters and pullets I like and cull the roosters I don't for the freezer and sell the pullets at the local poultry swaps for egg birds locally. It has always been my policy to only get birds from my own birds. I don't bring in chicks from other breeders in the area unless I know and trust them. So far all have been unvaccinated when they got here. I am leaning towards keeping birds unvaccinated and culling heavily for any illnesses to keep the flock healthy. They do free range over 2 and a half acres and are outside more than in. They have a coop inside our large barn that is very easy to take apart and clean and disinfect if needed. None of the 4 I have have been ill at all. They are outside even when it's below zero and seem to love free ranging even in the cold.

 

[LilyD]

Vaccinated VS unvaccinated birds together don't cause the virus. The virus causes the virus. The vaccine just keeps infected chickens alive.

There are light strains and hot strains of the virus. The light strain "only" kills at least half of all your birds. The hot strain kills all of them. They're both highly contagious and nearly impossible to breed for immunity or remove from the environment.

If your chickens get the hot virus strain;
By not vaccinating your chickens you stop the spread of the "hot" strain of the virus.... Because all of your chickens die so they can't spread it anymore. Because they're dead. This gives you a chance via quarantining unvacced birds to potentially prevent the virus in your flock.
By vaccinating your chicks, you sort of let the hot virus strain keep spreading because the chicks don't just die to the virus before they can't spread it. Then they have no symptoms but keep spreading the virus.

If you get the light strain of the virus in chicks, chances are good it won't kill them until they're in your flock unless you have a LONG quarantine period (upwards of 32 weeks but at least 10). If they have it and go into your flock then half your chickens are dead if they're unvacced no matter what you do cause it lingers and takes longer to kill the chicks and by the time they're dying they probably all have it. If you get the light strain and they're vacced they all have it, they're deadly to unvacced birds, but they all live.
The hot strain DID develop in response to the vaccine. The vaccine still works against the hot strain of the virus.

Also there are two vaccine options. One is more effective than the other.

If your chicks are vaccinated and never exposed to the virus it doesn't matter if they are mixed with unvacced birds or not. Nobody is sick or carrying the virus so it doesn't matter.

If you're keeping chickens as pets you may want to consider vaccinating to help keep them alive.
If you want to stop the spread of the disease you may want to not vaccinate, cull heavily for good health, and send suspicious deaths to a necropsy lab to keep tabs on if the disease shows up in your flock.
If you're breeding for more than yourself you may want to be unvacced so other people can rely on knowing your flock is Mareks free.
If you get the disease you have to be prepared to close your flock or go chickenless for years whether you're vaccinated or not.

This is 100% my biggest fear. That due to the vaccine being leaky that the virus will get worse and mutate while alive in my vaccinated birds and cause a more virulent strain of virus that will then take out my whole flock. I have always been very big on separate if any birds seem off from hatch on. If they act off I separate for a day and if they don't seem to be getting any better I'll cull if needed. Most of my roosters are used for meat in the end so I definitely would not want them vaccinated since we eat them. So I'm leaning towards not vaccinating them. I also tend to sell the extra pullets I get from hatching in the spring at the chicken swaps to other poultry members. I don't purchase poultry any birds I bring in come in as hatching eggs or are from my own flock. Once the birds leave here I don't bring them back. So other than wild birds and anything that might already be in the soil I don't think they would be exposed.

 

[CatWhisperer]

Mareks vaccine is made from turkey Mareks virus. It stimulates immunity withou causing disease in chickens. ‘Hot’ Mareks virus is a mutation of the chicken virus and is not associated with the turkey virus that vaccines are made from.

 

[ChocolateMouse]

That's not how it works, really. The vaccines that we have used on a global scale likely gave the hotter strain a place to develop, yes. But the vaccine still works against the hotter strain. The vaccine still works against mutated strains of the virus. And the chances of your flock suddenly developing an even more hotter strain of the virus that breaks through the vaccine is infinitesimal. Those kinds of mutations take many decades over the course of billions of birds. The mutation we have now doesn't even break through and we've been using the turkey vaccine for a good 70 years.

And in any case. If your chickens aren't vaccinated against Mareks and are exposed to Mareks, they're pretty much all dead anyhow. It's just that you know you have Mareks and what caused the deaths.

The vaccine itself does not effect meat quality. Neither does the virus, except organ quality. The vaccine goes through the body fairly quickly and there is no meat withdrawal period for the Mareks vaccine. Mareks is a species-specific virus, not a bacteria so there's no real risk associated with getting a low dose of the vaccine in your food.
Also, a vaccinated bird can't just "have" Mareks unless it's exposed to Mareks. The Vaccine isn't even made with chicken Mareks, it's made with the much less deadly turkey Mareks which chickens cannot catch.

The only thing that will give your chickens Mareks is another bird in the area that has Mareks shedding the virus in a place it can be carried back to your birds. (This can happen even on shoes or clothing, so practice good biosecurity first.)
If that happens, and your chickens are unvaccinated, you'll have massive losses. But you'll know you have Mareks. If that happens and they are vaccinated, they will live but you may never know you have Mareks. If that happens and your flock is mixed, your vaccinated birds will be fine and the unvaccinated ones will have massive losses and if you have a fair number of bird you're very likely to know it's Mareks. Either way you will have Mareks in the soil for the next 3-10 years.
If that never happens there is no difference between vaccinated and unvaccinated birds.

Whichever option is right for you depends on your goals. If it's more important to KNOW you have Mareks then it is to keep your birds alive, don't vaccinate. If it's the other way around, do.

(For reference, my birds are unvaccinated and I don't think people should. I think people should cull their flock if they have Mareks. I just want to make sure you understand what the real situation is without fear mongering.)

 

[LilyD]

That's not how it works, really. The vaccines that we have used on a global scale likely gave the hotter strain a place to develop, yes. But the vaccine still works against the hotter strain. The vaccine still works against mutated strains of the virus. And the chances of your flock suddenly developing an even more hotter strain of the virus that breaks through the vaccine is infinitesimal. Those kinds of mutations take many decades over the course of billions of birds. The mutation we have now doesn't even break through and we've been using the turkey vaccine for a good 70 years.

And in any case. If your chickens aren't vaccinated against Mareks and are exposed to Mareks, they're pretty much all dead anyhow. It's just that you know you have Mareks and what caused the deaths.

The vaccine itself does not effect meat quality. Neither does the virus, except organ quality. The vaccine goes through the body fairly quickly and there is no meat withdrawal period for the Mareks vaccine. Mareks is a species-specific virus, not a bacteria so there's no real risk associated with getting a low dose of the vaccine in your food.
Also, a vaccinated bird can't just "have" Mareks unless it's exposed to Mareks. The Vaccine isn't even made with chicken Mareks, it's made with the much less deadly turkey Mareks which chickens cannot catch.

The only thing that will give your chickens Mareks is another bird in the area that has Mareks shedding the virus in a place it can be carried back to your birds. (This can happen even on shoes or clothing, so practice good biosecurity first.)
If that happens, and your chickens are unvaccinated, you'll have massive losses. But you'll know you have Mareks. If that happens and they are vaccinated, they will live but you may never know you have Mareks. If that happens and your flock is mixed, your vaccinated birds will be fine and the unvaccinated ones will have massive losses and if you have a fair number of bird you're very likely to know it's Mareks. Either way you will have Mareks in the soil for the next 3-10 years.
If that never happens there is no difference between vaccinated and unvaccinated birds.

Whichever option is right for you depends on your goals. If it's more important to KNOW you have Mareks then it is to keep your birds alive, don't vaccinate. If it's the other way around, do.

(For reference, my birds are unvaccinated and I don't think people should. I think people should cull their flock if they have Mareks. I just want to make sure you understand what the real situation is without fear mongering.)

I agree totally and that is always my first instinct any sick birds or birds that show illness should be culled they bring weakness to the flock. I would rather cull the birds if I have an active infection and use a different area for new birds than to risk the potential to make things worse. I know it would take years and many birds but how many birds do we have currently on the earth and what percentage are vaccinated versus not. I know at least 1/3 of the back yard breeders up here in VT have told me they are vaccinating. I don't have any flocks close to me so as long as I practice good biosecurity then they will be good unless it comes in on wild bird dander. I have one pair of boots that is worn to the barn and no other places. All other footwear is never worn to the barn. I wash my hands before going out and again when I come back before taking care of my indoor pets. Part of my issue is that I am a great horror story fan and see way too many connections with this and some of the stories that always start out it wasn't a very bad disease just like a cold then it got worse lol. I'm super OCD about what I let on the farm and what I let near my birds so if it's not something that is transmitted via eggs that I hatch then I think it might have a hard time getting here.

 

[Eggs_With_Legs]

I am still slowly working towards that my ideal would be to eventually have a closed flock of Orps that I can breed and hatch eggs from and keep the roosters and pullets I like and cull the roosters I don't for the freezer and sell the pullets at the local poultry swaps for egg birds locally. It has always been my policy to only get birds from my own birds. I don't bring in chicks from other breeders in the area unless I know and trust them. So far all have been unvaccinated when they got here. I am leaning towards keeping birds unvaccinated and culling heavily for any illnesses to keep the flock healthy. They do free range over 2 and a half acres and are outside more than in. They have a coop inside our large barn that is very easy to take apart and clean and disinfect if needed. None of the 4 I have have been ill at all. They are outside even when it's below zero and seem to love free ranging even in the cold.

Other than not breeding my own flock, yours sounds almost identical in set up and behavior to mine. I would love to breed my own flock someday, I'm dying to hatch out another batch from this flock. I love the idea! I never used to vaccinate and I never had any problems, I've recently come across pecking with my integrated girls though, but that's all.

I think you should just go with your gut and continue on not vaccinating!

Let me know how it goes, best of luck!!

EWL