Evidence Update: Vaccination and Autoimmune Disease

One of the potential adverse effects of vaccination is the triggering of autoimmune diseases in susceptible individuals. There is some evidence in humans, for example, that the routine MMR vaccine (which prevents measles, mumps, and rubella) can trigger an autoimmine disease, called ITP, which destroys platelets and reduces a patient’s ability to form normal blood clots. The evidence suggests this occurs in roughly 1-3 children for every 100,000 MMR vaccinations.

While this is a real and serious risk, it is important to note that not only are the diseases prevented by this vaccine a much greater risk, but it turns out that these disease can also cause ITP and at a much higher rate than the vaccine (1 child out of every 3,000-6,000 cases). Therefore, the benefit of vaccination is clearly greater than the risk in this case.

There is, as always, far less data to determine what, if any, risk of autoimmune disease there is in vaccination of dogs and cats. Both ITP and IMHA, another autoimmune disease involving destruction of red blood cells, occur in dogs, and these have been reported to follow vaccination. However, the relevant research literature is sparse, flawed, and inconsistent. The bottom line from my previous review of the literature was this:

Bottom Line

  • Little evidence vaccination causes IMHA/ITP
  • No consistent temporal association
  • Data are weak
  • Overwhelming majority of vaccinated animals do not develop these diseases
  • Infection can be a greater risk for IMHA/ITP than vaccination
  • Don’t vaccinate more than necessary
  • Don’t vaccinate less than necessary
  • Don’t avoid vaccination out of fear of IMHA/ITP

A small piece of additional evidence was recently presented at the American College of Veterinary Internal Medicine (ACVIM) 2017 Forum.

Moon, AKB. Veir, J. Vaccination Behavior and Adverse Events in Dogs Treated for Primary Immune-Mediated Hemolytic Anemia (Abstract HM17) ACVIM Forum, National Harbor, MD, 2017.

This study surveyed the owners and veterinarians of dogs who had been diagnosed with IMHA. Such dogs are frequently not vaccinated once they recover from the disease because of concerns that vaccination might trigger a relapse. This is often done even when there is no specific reason to think vaccination triggered the initial episode. It is a reasonable precaution, but since it is not clear that vaccination actually is a risk factor for ITP or IMHA, it is possible that these dogs are being left vulnerable to infectious diseases unnecessarily.

In this small study, survey results were available for 44 dogs. There were several relevant findings:

  1. The average time from most recent vaccination to the initial onset of IMHA was 351 days. Such a long period makes it unlikely that vaccination was a major trigger for IMHA in many of these dogs. It still might have been in the subset who were vaccinated closer in time to the onset of their illness. This study found no such temporal relationship, but a different study design would be necesary to confirm that.Previous studies have found only a small proportion of IMHA cases received vaccinations in the 2-4 weeks before the onset of their illness, and most found no difference in recent vaccination rates between dogs who developed these diseases and comparison dogs who did not. So far, the overall data suggests that vaccination is rarely a proximal trigger for these autoimmune disease, though whether they play a role as an overall risk factor isn’t known.
  2. About half of the dogs had not been vaccinated since their IMHA diagnosis. This is consistent with the common practice of many vets to eschew vaccination in dogs who have had a history of autoimmune disease. However, about half of these dogs did receive vaccines after their diagnosis, and almost all of these were rabies vaccines. This is likely because rabies vaccination is legally required in most of the U.S. and exceptions are not always allowed for dogs with a history of autoimmune disease.Only 2 of the 21 dogs who were vaccinated following their IMHA had any reported adverse reaction. These two reactions were typical of the acute hypersensitivity reaction seen with vaccination. No relapse of IMHA or other autoimmune disease was reported in the vaccinated dogs. This suggests that such dogs may not be more sensitive to vaccination than other dogs, though again the size and methodology of this study is not adequate to demonstrate that with any certainty.
  3. Though this is just a small bit of data, it does fit into the larger context of existing evidence in dogs, and the much more comprehensive evidence in humans, suggesting that vaccines play an extremely small role, if any, in triggering such autoimmune diseases, While caution is warranted, and certainly unnecessary vaccination should be avoided on principle, there is no justification for extreme and confident claims that vaccines are a major cause of these autoimmune diseases in our pets or that what risk may exist outweighs the benefits of appropriate vaccination.
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65 Responses to Evidence Update: Vaccination and Autoimmune Disease

  1. Ruth says:

    My beautiful, healthy (7) year old lab received his annual shots Sept 27. He had never had an reactions. He received the rabies, DHLPP, Flu and Bordotella vaccines. Two days later he became confused, another day or two he began to trip going up the steps, the next day he was having trouble walking up the hill on our morning walk, the next day he would just look into his water bowl and did not know how to drink, he then began walking like a drunk person, he then did not know how to eat, he then started non stop pacing. We doctored with him every day for a month until we could see that our soul dog Ollie would never be the same in this life time and that he could not handle anymore. We lost him on October 24 almost one month after his shots. We are grieving in a huge way and questioning what went wrong. Are the shots to blame, did this healthy beauty have an underlying condition, was his time just up? We know that we will never know for sure what happened to him, but we would appreciate your thoughts.

  2. skeptvet says:

    I’m so sorry you had to go through this. Unfortunately, when hundreds of thousands of dogs get vaccinated regularly, the chances are that some who are going to get sick for other reasons will happen to do so following a vaccine. The way that we try to tell if the vaccines are a cause or a coincidence is with studies that look at many dogs who get sick with particular diseases and see if the number who gets sick within a certain time after vaccination is higher than the number who don’t get sick following vaccines. So far, we have not found any pattern for any particular disease that suggests the timing of vaccination is anything more than a coincidence. I don’t know what happened with Ollie or why, but there isn’t any reason to think the timing of vaccines was anything other than a coincidence.

    All the best.

  3. Ruth says:

    Thank you for responding. We have felt that there must have been an underlying condition that we had no idea about, even though his blood work was perfect and x Rays. His RBC plummeted from 7.68 to 5.37 one week after the shots. Wouldn’t that imply autoimmune involvement?

    I also worried about the quantity of immunizations at once. What is your opinion to that?

    Thanks for your help.

  4. Barry Herrero says:

    So sorry to hear your story. My 10 year old healthy soul mate dog got a rabies booster and developed auto immune anemia and died three months after the vaccine. She did not have any condition that would have caused the disease. The vaccine killed my beloved soulmate. I will never give my dogs rabies boosters.

  5. hannah says:

    I had the same coincidence with my beautiful retriever. He got his shots, along with a wellness exam in November at the vet we went to for years. The vet exclaimed how healthy he was and vitals were all good. Within two days, he slowed down and progressed to inability to eat. Within two months, he was dead. After multiple blood tests with platelets plummeting from normal range to “2” and severe anemia, his diagnosis was ITP. My intuition tells me he should still be here if I hadn’t gotten his annual vaccinations after age five. I fully understand the benefit of vaccinations and am the furthest in beliefs from any “anti-vaxer” out there.

  6. skeptvet says:

    Yes, I understand why such experiences, as painful as they are, can be so compelling. All I can say is that we vaccines may be a trigger for ITP, but so can many other things that we don’t see. The vast majority of ITP cases haven’t had vaccines recently, so we know there are. many other triggers. And, as you say, vaccines do a great deal of good. The sad reality is that even if vaccines prevent far more suffering than they cause, and they most certainly do, we can’t guarantee they won’t cause problems in some rare individuals. I still think that you made the right choice based on the best evidence.

  7. VK says:

    We have two black lab sisters we adopted as puppies from the humane society around 2008. In 2011, one of our labs developed IMHA (her immune system attacked red blood cells resulting in extreme anemia). What we went through with her was awful!! The prednasone made her back like raw hamburger (I have pictures of her back, the specialty vet had never seen anything like it and took pictures, I covered my dog with a winter jacket when I took her to the vet so people wouldn’t get grossed out in the waiting room, instead they would comment on her pretty jacket), we did a blood transfusion, I tried nursing her back to health, daily, for months and months. At one point early on, before the blood transfusion, we were going to put her down but my college-aged son insisted we didn’t, that she was tough and would survive.

    We spent thousands and thousands of dollars through this ordeal to try to help her survive. Luckily, she survived but has her life-long residual battle wounds of a hard time walking, weak hind muscles that makes it hard for her to get up or go up stairs, thick welts of scar tissue on her back (the thick fur grew back and luckily hides it) but she is happy and we’re happy to see her happy. I call her our “lucky-to-be-alive dog”. When we take her to the park and see her prancing around carrying her ball in her mouth, we are so very happy for her.

    Would I go through all of this again? Probably not. We don’t have the financial means to do it all over again nor do I have the energy or stamina to go through that again so I would probably have to let the dog go. However, we’ve met other people who have spent thousands of dollars to try to save their dogs too and at the time, when you’re in the whirlwind, you just say yes and yes to what the vets say they could try. And once you try one thing, like a blood transfusion, and it helps but doesn’t “fully” recover the dog, then you think well maybe a second blood transfusion will do it, and you end up in a cycle of attempts that pile up into a lot of money. I’m not faulting the vets in any way, it’s just the emotional events that occur that makes a person so blurred about what to do. And one vet was very realistic with us, cautioning us about the possibilities and even suggested it was maybe time to put her down. The vets really were awesome as we went through this process but we had to go to a specialty vet because the scope of our dog’s disease was far beyond what our regular vet was capable or equipped to handle.

    So what does my story have to do with this article? It really makes me question whether the immunization is what caused the IMHA vs a tick bite or other possibilities. We will never know unless there’s a way to test her blood now for specific antibodies or whatever they would test her for.

    Also, we have NOT immunized her at all since she recovered back in 2015 per our vet’s recommendations. In fact, we just had a long, serious discussion with our vet yesterday again about whether we should give her the rabies vaccination because we take our dog to the dog park, and our vet (and us of course) is still extremely apprehensive to vaccinate her. Why? Because it could kill her.

    And if our dog would accidentally cause an open wound on someone, like scratched a person’s arm with her tooth or something and broke skin, they could insist our dog get tested for rabies. How do you test a dog for rabies? You have to kill them.

    So we’re faced with a choice of 1) letting our dog live out her life (she’s almost 11 yrs old now) or 2) giving her a rabies vaccine that could kill her and may never have been needed in the first place for the likely short couple of years she has left. And if we choose option 2 and she dies, all the effort and money we spent to save her in the first place is negated.

    And while I never gave a second thought to our other black lab who has been fine, now after reading the responses above and this article, it concerns me whether our other black lab who just got her vaccines yesterday could develop IMHA. Ugh!

  8. L says:

    Your dog has an autoimmune disorder. Just ask your vet to sign a waver for the rabies vaccine.
    It basically says that your dog cannot have the rabies vaccine due to a medical condition.
    I would give up the dog park and keep the dog on leash whenever outside.

    “I have examined the animal above and determined that, in my professional opinion, there is considerable risk of harm to the animal from the administration of a rabies vaccine as required by law”
    You can present this when you take your dog for emergency care, some town halls accept it and allow you to license your dog.

  9. Jessica Tr says:

    You have some alternatives. First, you can do a titer test for rabies. If you have a recent titer that shows good levels of antibodies (I am not a vet and tbh I don’t know if it’s antibodies specifically they test for or what, but the levels from the rabies titer show how much immunity they have), you know your dog is safe from infection and cannot infect anyone else. It might be of benefit in a legal situation as well, although no guarantees there. Titer tests are more expensive than just giving the shot, so even in a few forward-thinking states where they are allowed as an alternative to vaccination, people tend to choose the cheaper shot instead.

    By the way, in Guam, which is a rabies-free island, they quarantine dogs for bites instead of the necropsy test. My understanding is that you don’t get animal carriers that are asymptomatic, so if they show no symptoms after the quarantine period they are considered uninfected. This is how it is done in my current mainland US state for dogs and cats as well, except we can home-quarantine here I believe. Raccoons, while allowed as pets here, are not given the same exemption and are immediately euthanized and sent for necropsy. I am a bit shocked that there’s no legal quarantine option where you live.

    The other option you may be able to try that one of my vets mentioned is to do partial vaccines to spread it over a period of time. This is mostly for if your dog were to fail the titer. This method of administration is a bit off-label, so it might not hold up legally, but it seems like it could be worth a try, especially if you can rerun the titer afterwards.

    My dog just came down with ITP recently and I have been trying to decide what to do about her vaccs myself. I will probably just run a titer annually and, if/when she eventually loses immunity, I will decide at that point how hard it would be to keep her safe from situations in which she could possibly get infected or become cause for concern. If we are still in our current state, I don’t think I will have to vaccinate her again, as she doesn’t have much of a social life and is retired from service work.

  10. Jessica Tr says:

    Are vaccines still effective on pharmacologically suppressed immune systems? So if my dog is at a maintenance level suppressive dose, is the immune response to the vaccine also suppressed? If we upped the dose as a way to try to prevent the ITP from flaring up again, would that make the vaccine useless?

  11. Jessica Tr says:

    Has the spreading of a vaccine dose over several days ever been looked at? I had a vet mention it to me as an option for a very small older dog, but it sounds like it might defeat the purpose of vaccinating at all.

  12. skeptvet says:

    There are a couple of issues involved here. The first is safety, and the second is effectiveness.

    Killed vaccines are considered safe in people and pets with a suppressed immune system. Modified live vaccines are usually not recommended because there is a theoretical risk of the weakened organisms in the vaccines being able to cause illness in people without normal immune function. For dogs, this probably means avoiding live Bordetella vaccines and modified live DAPP vaccines. Of course, such dogs should also then be kept away from other dogs or areas where they could be exposed to these diseases, since such exposure is much more dangerous than the vaccines.

    It is not clear how well vaccines work in immunocompromised patients studies of people have shown steroid treatment does not reduce the effect of the flu vaccine (https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4653723/), and one study has shown dogs on chemotherapy have the same response to vaccination as healthy dogs (https://www.ncbi.nlm.nih.gov/pubmed/16594592). However, it is possible vaccines may sometimes be less effective in some individuals on immunosuppressive medications. They wouldn’t be “useless,” and some protection is probably better than no protection, but they might not be as effective.

  13. skeptvet says:

    This doesn’t really make sense from a immunologic point of view. The way vaccines work is that an amount of antigen at or above a critical threshold level triggers a complete immune response. Any amount below that level triggers no response, and any amount above that level triggers exactly the same response as the threshold level. The immune system is like a traditional light switch, all on or all off, not a dimmer switch like many medications. This is why reducing the “dose” of vaccines, or spreading the vaccine “dose” out over several days doesn’t make sense.

    I’ve written about this in more detail in this post.

  14. Lenore says:

    I have a 18 week old puppy who has been diagnosed with Polyarthritis +/- Hypertrophic osteodystrophy. The diagnosis is not conclusive, but overall they believe it is some type of autoimmune disease. She has been hospitalized twice, once at around 11 weeks and once at around 16 weeks. She is responding to prednisolone. My concern is the 2nd onset was 3 days after her initial distemper shot. She is scheduled for her next Distemper/Parvo shot in a week or so. I’m very concerned because because of her suppressed immune system and how she could react and that both my normal vet has no experience with this and the critical care vet has very little experience. I am very reluctant to allow her to get vaccinated right now.

  15. skeptvet says:

    I’m sorry you are facing this awful dilemma.

    As far as whether the vaccination is a factor in the development of your pup’s illness, it is pretty unlikely. As you can see from the articles here, despite millions of dogs getting multiple vaccines over decades, and many, many more children get even more vaccines, there is very little evidence of autoimmune disease resulting. If it happens at all, it is exceedingly rare, and the risks of not vaccinating are certainly greater than the risks of giving them.

    There is one study that has specifically looked at immune-mediated polyarthropathy in dogs and timing of vaccination, and it did not find an association. Like any disease that developed during the time of life when we are giving vaccines, it is tempting to worry that the vaccines are responsible, but the evidence says this is unlikely.

    In terms of what to do about vaccination in the future, it is generally not recommended to give a modified live vaccine to a patient on immunosuppressive doses of steroids. This is mostly because it probably won’t work as well as it normally would, but there is also a small chance of harm. It makes sense to delay the further vaccines until after your pup is off of the high-dose steroids.

    Unfortunately ], though, this means it is VITAL that you prevent any exposure to possible sources of infectious diseases. She should have no contact with dogs outside the household or with any place other dogs may have eliminated. This is tough since it prevents some important socialization experiences, but your pup is at greater risk of infection both because of incomplete vaccination and because of the steroid medications.

    In the future, it is unlikely that vaccines will trigger additional episodes, but no one can say for sure. You can consider regular antibody titers as an alterative to vaccination, but if the titers are low I would still recommend vaccinating once your dog’s condition has resolved and she is off of the steroid.

    Good luck to both of you.

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