Vaccinate or Not

[FortCluck]

The vaccine does not cause Mareks. The vaccine can hide a Mareks infection but does not cause one.

The vaccine is not even made with the same virus. It's made with the Mareks turkey virus.

Isn't it not even a live vaccine? It couldn't cause it if it's not live

 

[Mixed flock enthusiast]

Isn't it not even a live vaccine? It couldn't cause it if it's not live

Marek’s disease vaccines are live viruses. The older one that you can buy online:

https://www.strombergschickens.com/product/Mareks-Vaccine-1000-Doses/Poultry-Vaccines-Blood-Tests
is the cell-free, herpesvirus of turkeys, which protects against the less virulent Marek’s disease virus strains. It is a turkey herpesvirus that is not pathogenic you chickens. This is the one used in most backyard poultry. The newer vaccines (like Rispens) that some commercial hatcheries use is a different herpesvirus strain that is more effective against the more virulent MDV strains but isn’t directly available to backyard keepers. They are also live or modified live vaccines. However, I don’t know of reversion to virulence being reported for these newer vaccines.

 

[FortCluck]

Marek’s disease vaccines are live viruses. The older one that you can buy online:

https://www.strombergschickens.com/product/Mareks-Vaccine-1000-Doses/Poultry-Vaccines-Blood-Tests
is the cell-free, herpesvirus of turkeys, which protects against the less virulent Marek’s disease virus strains. It is a turkey herpesvirus that is not pathogenic you chickens. This is the one used in most backyard poultry. The newer vaccines (like Rispens) that some commercial hatcheries use is a different herpesvirus strain that is more effective against the more virulent MDV strains but isn’t directly available to backyard keepers. They are also live or modified live vaccines. However, I don’t know of reversion to virulence being reported for these newer vaccines.

So it can't cause Marek's if you vaccinate?

I may try to get vaccinated chicks sometime to see if I can see any difference, but that will be later down the road.

 

[Mixed flock enthusiast]

So it can't cause Marek's if you vaccinate?

I may try to get vaccinated chicks sometime to see if I can see any difference, but that will be later down the road.

No, the vaccine doesn’t cause Marek’s disease. There is concern that the widespread commercial use of the most effective vaccines in millions of commercial birds every year is increasing the virulence of Marek’s disease viruses. However I don’t see that backyard chicken keepers have anything to do with the development of more virulent strains; we are just the unlucky recipients of this trend...

 

[Trevorusn]

This thread is quite the read. Suffice to say, the call to vaccinate is just as uncertain now as it was some years ago and remains a divided topic. I do agree however that there really should be a push for more research into more effective Marek's control, from biosecurity to actual effective vaccines that actually defeat Marek's rather than delay or seemingly hide it. My flock remains unvaccinated, as I believe TSC/Hoover do not do standard vaccinations, and thus I always look for unvaccinated additions.

 

[RobynNicole]

I'm with the 21.8% (currently at time of this post) on the results who does and absolutely will vaccinate - when needed. Blasted with Marek's which does not always have typical symptoms, attacking originally 4 hens at various ages of 1 to 4 years of age, all died. One survived, however, does walk with a limp as her sciatic nerve to her right leg was affected. This survivor is going to be 10 years old this May. She was 4 when Marek's first hit. Vaccines were not offered at the time though the feed mill I had ordered my first chicks from and being new to chickens, I knew nothing of this disease.

My last 2 ordered chicks were vaccinated directly from the hatchery. I would not deny them the opportunity to build up their immunity to this horrific disease. No, vaccines do not "prevent" a disease/virus from attacking. It gives the body a taste of what that pathogen looks like and it learns to build up its immunity to that pathogen. When and if that pathogen does show up later in life, their immune system recognizes that virus and knows to attack it. Why would I not protect my beloved girls in any way that I can? I protect them from predators and this is no different in my opinion. Speaking here as a lifer in the medical field who adores every single one of her 12 variety of hens.

 

[Mixed flock enthusiast]

I'm with the 21.8% (currently at time of this post) on the results who does and absolutely will vaccinate - when needed. Blasted with Marek's which does not always have typical symptoms, attacking originally 4 hens at various ages of 1 to 4 years of age, all died. One survived, however, does walk with a limp as her sciatic nerve to her right leg was affected. This survivor is going to be 10 years old this May. She was 4 when Marek's first hit. Vaccines were not offered at the time though the feed mill I had ordered my first chicks from and being new to chickens, I knew nothing of this disease.

My last 2 ordered chicks were vaccinated directly from the hatchery. I would not deny them the opportunity to build up their immunity to this horrific disease. No, vaccines do not "prevent" a disease/virus from attacking. It gives the body a taste of what that pathogen looks like and it learns to build up its immunity to that pathogen. When and if that pathogen does show up later in life, their immune system recognizes that virus and knows to attack it. Why would I not protect my beloved girls in any way that I can? I protect them from predators and this is no different in my opinion. Speaking here as a lifer in the medical field who adores every single one of her 12 variety of hens.

Wow - that’s an incredible survival story for your 10 year old hen! Gives me hope that some of our older, 1.5-2 yr old unvaccinated chickens will make it. Most of their compatriots have dropped, one by one, at various stressful life events: chicks, adolescence, point of lay, resumption of lay after winter, after an injury, etc. A rush at first and now more slowly... Knock on wood, but we haven’t yet lost one of our vaccinated chickens...

 

[KnightsMist]

Right, it's about a lack of support for the salmonella vaccine. For example, if large hatcheries offered it I'd use it every time because they could USE all 5000 doses and the cost would be minimal. If it had widespread public support it would probably also be available in less expensive smaller dose bottles that I could use.

Here's an article on it;
https://www.nytimes.com/2010/08/25/business/25vaccine.html

Basically I'd use it if I thought it would do any good and not triple my cost of production for chicks. As it stands I have a fairly healthy flock and I feel safe eating their eggs over easy or even raw in some cases. But I would take advantage of this vaccine if it were socially or economically beneficial to do so.



Luckily that's not the case with human vaccines at ALL. Most human vaccines, including the flu shot (when you happen upon the correct strain) produce what's known as a sterile immune response. As in, your immune system recognizes the disease and eradicates it causing it to spread less. Even in the case of human flu vaccines for the wrong strain, if you are vaccinated for ANY flu and get a different strain than you're vaccinated for your immune response is stronger and the disease reproduces in your body less, and therefore sheds less virus.

With Mareks, the vaccine isn't actually developed from chicken Mareks it's developed from an adjacent species Mareks. What happens is instead of producing a greater immune response, basically the birds body almost learns to ignore the Mareks inside of it and not react to the virus by developing tumors or symptoms. It doesn't actually fight the Mareks virus, it just doesn't get hurt by it. This creates a sort of silent carrier of disease, close to a human having contracted chicken pox or mono - the condition is still there and still spreadable, it's just not effecting THAT particular bird. Because the bird is still healthy, in fact, the virus has even more resources to reproduce than a sick bird (who may stop eating and die) so they shed MORE of the virus because of its greater presence in the body, not less.

This is also why the chicken pox vaccine for people is relevant even though a more natural immunity exists. If you get the 'pox you have a chance of relapse (shingles) or passing it on still. If you get the vaccine it actually produces a STERILE immune response. No shingles, no chance of relapse, no passing it on even for a brief window, nothing. It just goes away. Through methods like this you can actually eliminate entire diseases. You can't if people are still catching it through otherwise healthy individuals passing it on. And that's especially true for Mareks.

I'm still new to all of this and learning. I had assumed that when I get chicks, I would get them vaccinated, thinking merecks vaccine works like those in people. Your explanation was so helpful- thank you for your detailed clarity.

 

[ChocolateMouse]

I'm still new to all of this and learning. I had assumed that when I get chicks, I would get them vaccinated, thinking merecks vaccine works like those in people. Your explanation was so helpful- thank you for your detailed clarity.

To be fair, a few select vaccines in people are some amount leaky. (Most are sterile though, and Mareks vaccine is 100% leaky.) And basically, if your chickens are vaccinated they're more likely to live if they do catch Mareks. But I'm just way more comfortable with my chickens dying to help prevent the spread of a disease than with people dying.

The question of what will you do if your unvacced chickens DO get Mareks is a serious one to think about. Be aware that a dead chicken spreads Mareks less but is still dead. If you have Mareks in an unvacced flock you need to be prepared to cull birds.

Not everyone is comfortable with that.

 

[KnightsMist]

To be fair, a few select vaccines in people are some amount leaky. (Most are sterile though, and Mareks vaccine is 100% leaky.) And basically, if your chickens are vaccinated they're more likely to live if they do catch Mareks. But I'm just way more comfortable with my chickens dying to help prevent the spread of a disease than with people dying.

The question of what will you do if your unvacced chickens DO get Mareks is a serious one to think about. Be aware that a dead chicken spreads Mareks less but is still dead. If you have Mareks in an unvacced flock you need to be prepared to cull birds.

Not everyone is comfortable with that.

Thank you- clearly, still much to learn and ponder before I get chickens!