Today I thought I’d make a quick post about Mareks in chickens and my thoughts on the Mareks vaccine, when I realized that my thoughts on this subject spread over into my thoughts on vaccines in general. This is a touchy issue for some people. My information is factual, hard science. My opinions and actions are just that. Opinions and personal choices.
So first, some facts about Mareks. You can find most of this info right here in a well thought out article that I do not care to replicate… But here are some of the cliffnotes.
Mareks is a highly contagious and fatal virus with no cure and is not zoonotic or dangerous to other animals in the environment. The chicken version is contained to chickens and it’s really bad in chickens. It lives outside the chicken for a minimum of five months, and possibly years. It kills chickens in a horrible way, with paralysis, tumors, diarrhea, starvation, blindness and breathing issues. The symptoms fade in and out over months and kill very slowly. A chicken typically starts shedding the virus after 10 days post-exposure and shows symptoms after a month, and typically dies shortly thereafter. It can take up to six months before symptoms show after exposure to the disease in certain rare cases, though.
Now here’s some info about the vaccine. The Mareks vaccine works by offering the body something similar to Mareks to target and “learn” to fight it off. What is introduced into the chickens is the “turkey version” of Mareks, which has a similar makeup to the chicken version but can’t infect or be shed by chickens. It must be administered within 36 hours of hatching. The Mareks vaccine is NON STERILE, not to be confuse with terms like live/dead vaccines which is irrelevant. A non sterile vaccine means the vaccine does not prevent the virus from infecting the chicken, stop or slow the shedding of the virus nor cure the virus. It instead means that if the bird develops the virus, its immune system will be able to fight back and not develop the life-threatening symptoms that the virus creates because it already knows that it is a threat. All it stops is the symptoms, NOT the actual disease. A vaccinated bird can still be infected with Mareks. The vaccine used to be considered about 90% effective at stopping symptoms but more recent studies have shown that Mareks is mutating faster than vaccination can keep up with and that number is slowly dropping. In some places it’s now considered less than 80% effective, which is below herd immunity levels.
This last part is very similar to the way some human vaccines work and it’s one small piece of the puzzle of immunology. It’s part of why even if someone is vaccinated they could possibly still catch a disease, and it’s why even if we vaccinated the whole human population for 100 years we may never get rid of contagious diseases because all it takes is one asymptomatic person to spark a whole outbreak. The reality is, we may never show a symptom, but the disease might still be around. It’s why they still suggest vaccines for “eradicated” diseases that we’ve been vaccinating against since the beginning of vaccinations.
That being said, I am pretty firm on my stance. I believe in the power of natural immune systems. They’re incredible, they have the power to fight diseases like crazy and they are also genetic. If you never vaccinate a population of chickens you arrive at two outcomes. Either; A) The population of chickens catches Mareks, it’s super contagious and fatal and they all die; or B) The chickens keep living, either by having built a total natural immunity to the disease or by the disease having run it’s course long ago and no longer having had any prey the disease dies out. It may take a very long time indeed to reach one of these outcomes, but a little dose of selective breeding goes a long way. Animal husbandry is our own little micro eugenics program to breed bigger, faster, better, stronger and more immune chickens. We can also know when a disease is in our flock and eliminate all of the diseases “food” (in this case, chickens) so it dies out before it can spread. That’s what breeding IS. It is deciding who lives, breeds, and dies based on arbitrary traits and goals. Selective breeding IS eugenics.
If you vaccinate a population of chickens against most diseases you have to keep vaccinating them against it forever. This happens in humans sometimes too. We vaccinate against a disease, and maybe it is a sterile immunity, most human vaccines are sterile under the correct circumstances, which means that the immunity prevents the disease from infecting the body and the disease will never shed from the body even if they are exposed to it. Maybe some aren’t and that disease gets passed around asymptomatically forever. Maybe some people have weaker immune systems and what is normally a sterile vaccine is instead one that produces an asymptomatic carrier. Maybe a disease has animal carriers and is hard to eradicate from the environment, like flus. But the Mareks vaccine is NOT sterile EVER. If we vaccinate against Mareks we have to ALWAYS vaccinate against Mareks the way we ALWAYS vaccinate against tetanus. And the reality is that at best the Mareks vaccine works 90% of the time. The same thing goes for avian diseases like Newcastle, which is also carried by wild birds. We have to vaccinate forever, and still expect losses.
So here’s how I see it. I vaccinate myself and my dogs against fatal and common diseases. I don’t vaccinate my livestock unless the vaccine is a sterile vaccine.
By doing this I am guaranteed of one of two things in my birds… A strain of chickens with total immunity to Mareks or a flock that is completely free of Mareks. And what happens if my flock gets Mareks? The same thing that happens if my flock gets bird flu. The whole flock is killed in a comprehensive disease eradication program, all my equipment gets burned or torched and I do not put chickens on that land again for at least one year. Is that harsh? Very! It’s also the reality for people who are monitored for Avian Flu. And because of that, the Avian flu has not been spread across the whole nation killing half of the USAs chickens, possibly infecting and killing people, putting countless farmers out of work and sending the price of chicken meat skyrocketing. It’s about being responsible for the good of everyone.
But there is surprisingly no such program in place for Mareks, Newcastle or other severe and contagious chicken diseases. I’m committing myself to these actions willingly even though it may mean I loose everything for a year or more. I have done this for avian flu by becoming NPIP and I’m doing it for other diseases because I would like to see our birds in the USA either have a natural immunity to Mareks or I’d like to be able to proudly say that my flock is 100% clean. If my birds get sick, I cull them. Your vaccinated birds? Who knows if they carry Mareks or not? Am I going to bring home your supposedly “clean” bird, that acts totally healthy, and it’s secretly a ticking time bomb? I’m really concerned by the idea that 90% of vaccinated birds could be carrying Mareks and nobody would ever know it until my whole flock dies. The best part is that there’s no way (in a flock of all-vaccinated birds) of proving to me that your Mareks vaccinated birds DON’T have Mareks! And that is fine if the vaccine is dirt cheap and I want to vaccinate every single chick I raise out at hatch for the rest of humanity’s existence with no chance of eradicating the disease or growing birds that are immune to it and accepting that at least 10% of our birds die to this disease, and another 10% die to some other disease there’s a vaccine for, etc. But I think we can do better.
The price of such a program is steep, but the prices when it’s not followed are even steeper. There are countless people with their precious backyard flocks of PET chickens that come down with Mareks and they couldn’t imagine culling them, not even to protect the entire rest of the chicken population in the united states. This behavior was the start of a severe Newcastle outbreak in 2002 in California. Official reports state that it was a backyard flock with inadequate health management programs that was the source of the outbreak that spread to commercial flocks, other states, and cost farmers millions of dollars. People’s flocks of pet chickens were seized by government officials for destruction after a state of emergency was declared. All because one person didn’t cull unhealthy birds and report sickness in their flock. If someone moved in next door to me and got chickens, there would be nothing stopping them from putting unhealthy Mareks-laden “vaccinated” birds next to me and I’d never know it until my flock started dying. And if we worked together, agreed to BOTH remove our flocks for a year, and then get healthy birds a year later, we could eliminate Mareks in our neighborhood. Programs like this could eliminate Mareks from the USA entirely in a decade. And it’s simple; if your birds get Mareks, cull them. Follow good sterilization procedure, don’t put birds on that land again for at least a year, and we could see a massive eradication of a disease in a way that we will never see with the non-sterile vaccinations.
Unfortunately, too many people want to cling to their pet chickens. There are topics all over the internet about how to keep disease laden chickens alive, how to fight the government or other chicken facilities that are calling for your flock to be culled, and how to keep your chickens in hiding so that they can’t find your sick birds to kill your sweet little poopsy woopsies that happen to be costing all of the farmers around you lots of money and lives. The refrain of “Why should my vaccinated birds have to die just because you don’t want to vaccinate yours!?” is often heard and sometimes it gets countered with “Why should my healthy birds have to die for your sick ones!?”. People find themselves at an impasse with nobody to enforce or regulate a disease. We COULD do better, but unless there’s a national program for Mareks like the NPIP for avian flu, we can’t because there’s nothing TO enforce. So for now I will continue to cull for health and anyone who buys from me can be guaranteed that they are getting a healthy bird that is 100% Mareks free.
But I vaccinate my dogs and myself. Why? The first reason is because, like I stated earlier, most human vaccines are sterile, which means that even if I am exposed, the disease will not cause me to catch and shed the disease. That means that by vaccinating against the disease we are essentially seeking the natural solution of denying a disease its food source without killing people who get the disease. We are starving the disease out, and someday if every single person is vaccinated consistently for a time, we may actually see the diseases removed from the planet. This cannot happen with vaccines for things like Mareks, Newcastle and tetanus because of outside influences.
And yet I still tell people to get their tetanus shots. I got mine. My dogs have rabies vaccines and not just because of the law. The reason is because chickens are, in a way, disposable. They’re the goldfish of the avian world. You may love them, they may be smart, but ultimately they’re a small bundle of birds worth MAYBE $100 each if you have some extremely rare flock. Most people could find replacement hens for $15 a pop that are younger, healthier and produce more eggs. A year without chickens is not the end of the world. They live and die fast. A 6-month-old chicken is an adult. A 4-year-old hen is old. A 10-year-old hen is probably dead. Most people replace their hens within 3 years. What is one year without your hens? And further more, we raise them for food. No matter how much you love your mouse, chicken or goldfish… Ultimately the species is primarily raised to be eaten by something else.
But my dogs are not disposable. We chat together, they keep me sane, they are wildly sociable and designed by nature to attune themselves to my every request. They give me exercise and joy, they are robust and personable. I have thousands of dollars invested in each dog solely as a companion animal. I expect them to do what jobs they have (the occasional cart to be pulled, guarding my house, herding chickens, or carrying a backpack on a hike, etc) and eventually retire peacefully to my home. They are not disposable, replaceable animals. They may stay with me for 20 years, or a fifth of my whole life on this earth. They are not a $15 animal raised en masse for food that I would likely replace in three years anyhow.
And people fit the “disposable” bill even less so. So yes, I have avoided some vaccines for non-fatal conditions (flu shot is silly IMO) and gotten others for conditions that are more likely to hurt me (tetanus comes to mind, given my work). For me to endorse not getting vaccines for serious conditions for people is like telling someone to treat humans like disposable chickens. The price of seeking factual natural immunity is awfully steep to pay. The price is eugenics. And if you’re supporting nature and natural systems, you can look at chickens to see how much it would take for that to be effective. I’m willing to cull fifteen birds, or even one hundred birds, or a thousand, or a million, to keep a disease from spreading without vaccines. So unless you endorsing mass genocide for a species (which in the case of chickens, I am), you might wanna consider vaccinating. Because that’s how immunity works. Immunity is bred in, not magically obtained. So please, always use sterile vaccines, and you might want to consider non sterile vaccines as well. The one in a million chance of having an allergic reaction is probably worth not requiring genocide for the human race.
quarteracrehome 
Interesting blog post. I feel much the same way.
Thank you, Robin. 🙂 I wanted to make this post because I was feeling some frustration about someone on craigslist with a bunch of beautiful, fancy breeds of chickens that I want. But they are constantly posting about how you should also vaccinate for Mareks in their ads and bragging about how every single one of their birds is raised in a contained environment and vaccinated against Mareks….. But to me that just says they don’t understand how the vaccine works and how it’s a ticking time bomb that forces everyone to vaccinate for it for the rest of history. It also means I can’t bring their birds home because I don’t want to risk Mareks in my flock.
What does Mareks really look like? If you buy chicks from a hatchery, are they usually vaccinated against Mareks? In that case, we are bringing the disease to our homesteads every time we purchase a chick…ugghh!! I have lost a couple of hens (3 yrs old plus) over the last year that I got as chicks from a local farm supply store…they started with a watery diarrhea and wasted away (we culled each of them after a short time of them not getting well.) Is this Mareks? None of my hens hatched on our farm (offspring of these hens) have shown any signs. I don’t vaccinate chicks I hatch, and as your post suggests, I’m thinking if this is Mareks, they have built up a natural immunity.
I’m not really qualified to diagnose Mareks. I would suggest reading this article (linked to at the top of this article) for more info on Mareks and trying to diagnose it. My flock is, and always has been, clean and Mareks free.
http://www.backyardchickens.com/a/the-great-big-giant-mareks-disease-faq
To me, your description does not immediately smack of Mareks. Did you autopsy the birds and observe them closely? Mareks often manifests as tumors and blindness, neurological symptoms (loosing control of limbs, not moving much because of it), all of which can look like strange behavioral problems from the outside. They also tend to have diarrhea and refuse to eat, but this could be a symptom of a much more common condition like cocci gone out of control. Mareks is hardly the only disease or condition known to poultry…
Just loose stool and wasting away could be about half of the poultry problems in the world. It’s the bird equivalent of a human saying they have a slight fever and feel a bit nauseous. Is it a flu? Mono? Appendicitis? An ulcer? Cancer? Ebola? Something less common? Who knows. You need more info to go off of. It could be something as simple as they needed to be wormed.
As for large poultry suppliers, they have lots of biosecurity measures outside of vaccination and not all poultry suppliers vaccinate in advance. For example, Meyer hatchery here in Ohio does not pre-vaccinate their day-old chicks. If a large, major poultry supplier such as Meyer or Ideal hatchery were to get Mareks in their flock it would be known very quickly even if they vaccinate every bird because the vaccine is not 100% effective and they have so many birds. It would produce unacceptable losses (10-30%) in their growing birds and their chicks would have a higher die-off rate then a healthy flock. It would soon become a public relations nightmare with dozens of people reporting die-offs in birds from that company. Also, since these companies sell their supposedly healthy birds to people with unvaccinated flocks, the reality is that they could be facing down class-action lawsuits for angry chicken owners nation-wide. It would be very public within a month and the extremely large company may very well go under because of it. So they do everything in their power to stop that from happening. NOTHING that is not 100% sterile may go in or out of their chicken houses. All clothing must be changed before entering their buildings, there are shoe sterilization baths, plastic bio-security suits, the whole nine yards. If you ever wonder why large poultry farms (either hatcheries or food) won’t let you visit their facilities… This is why.
A smaller producer (that has specialty poultry, a small flock, and serves a small area) has no such extreme measures because those cost money. For example, I take biosecurity semi-seriously. I have a special pair of shoes I wear to my back yard, and I try to change clothes if I have been wearing those clothes out at a potential disease-harboring location (IE feed store or farm) before handling my flock. I am NPIP. I quarantine new birds for weeks before introducing them to my flock. I can strongly claim I have a clean flock. If I vaccinated and had Mareks in my flock of 12 birds, I might see three die, go down to 9 birds, and shrug it off as “well it could have been anything” (like your birds) and ignore it, especially if I think of my birds as a “pet” flock that I don’t want to cull and am willing to turn a blind eye to contagions. You’d have no way of knowing if I have Mareks in my flock if I vaccinated, and a few chicks, eggs and adult birds going to enough inexperienced hands would be an easy cover for any illness the offspring carry. BUT, I do NOT vaccinate my flock for this disease so at least half of my flock has NO immunity and they are healthy and kicking. (The other half is unknown. I don’t know if they are vaccinated or not.) Because half of my flock is unvaccinated, I know almost immediately if my flock has something bad, unlike someone with a vaccinated flock which may loose a couple of birds and not think twice.
So my concern with Mareks vaccines is not from large suppliers, although I prefer sourcing from suppliers that do not pre-vaccinate, and I encourage people to buy from large hatcheries if that fits their needs. My concern is with back-yard chicken keepers and breeders who do not take full responsibility for the spread of contagions within the chicken community. It’s not a large supplier I worry about who will immediately cull a chicken at the first sign of illness to keep their multi-million dollar business running, it’s my neighbors and the other people at feed stores who won’t be willing to cull their poopsy-swoopsy-chicky-boo that’s sick, or the rest of the flock, even if the potential for being contagious and killing other flocks is high.
And on another note, do not purchase from My Pet Chicken as they are a middle-man between small, unregulated producers and “pet” chicken owners. Half the birds you get from there aren’t even the breed they claim to be and have sketchy health backgrounds. MPC is not a hatchery.
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