VACCINES

Too Many Shots!!!
By Gary VanEngelenburg DVM,CVA

A practice that was started many years ago and that lacks scientific validity or verification is annual revaccination. Almost without exception there is no immunologic requirement for annual revaccination. Immunity to viruses persists for years or for the life of the animal. Successful vaccination to most bacterial pathogens produces an immunologic memory that remains for years, allowing an animal to develop a protective anamnestic (secondary) response when exposed to virulent organisms. Only the immune response to toxins requires boosters (e.g. tetanus toxin booster, in humans, is recommended once every 7-10 years), and no toxin vaccines are currently used for dogs or cats. Furthermore, revaccination with most viral vaccines fails to stimulate an anamnestic (secondary) response as a result of interference by existing antibody (similar to maternal antibody interference). The practice of annual vaccination in our opinion should be considered of questionable efficacy unless it is used as a mechanism to provide an annual physical examination or is required by law (i.e., certain states require annual revaccination for rabies).(1)

The above paragraph was taken from Kirk’s Current Veterinary Therapy XI published nine years ago. This publication is found in almost every small animal vet’s office. So, what has happened? Does your veterinarian still recommend annual vaccinations? The reasoning often is that we give them simply because of habit. Some hint that they are aware of some controversy but are “playing it safe”. The sad truth is more one of economics to most practices as annual vaccinations makes up a large portion of the income for many practices. I really think many veterinarians don’t want to hear the truth about the hazards of giving annual modified live virus (MLV) vaccines.

Fortunately, for our pets’ sake, public awareness and medical awareness are starting to surface and change is starting. Last year the National Association of Feline Practitioners started recommending it’s members limit booster vaccines to no more than once every 3 years. Colorado State has a website up and running (2) detailing which vaccines to use and NOT to use and recommends a schedule of no more than once every three years for boosters. They go on to recommend using only “core” vaccines in both cats and dogs. This includes canine distemper, parvo, and adenovirus type 2(for hepatitis protection) and parainfluenza. Feline vaccines include rhinotracheitis and panleukopenia only. Rabies for both species varies some from state to state so may be annual or once every 3 years.

The annual vaccine habit wouldn’t be so bad if it was as simple as not being necessary. The truth is that there are harmful side effects to giving MLV vaccines every year. More and more research in this area is coming up with the vaccines causing autoimmune antibody production to many organs and body tissues. (3) When you consider that immune titer studies indicate a minimum of 7 years protection after a single dose(4) where do we get the annual booster idea anyway? I think we, as veterinarians, are obligated to do what is best for the pet. Giving unnecessary vaccines , in my opinion, is unethical and, in some instances, bordering on malpractice.

Another factor to consider is safety when giving MLV vaccines, especially when giving multiple antigens at the same time. Most of our continuing education on new vaccines and vaccine combinations comes from representatives of the companies selling the product. I can’t help but think there may be a bit of bias involved here. Anyway, we are constantly told that the multiple antigen products are safe, convenient and effective. I remember two cases in the past year with perfectly normal, happy, apparently healthy cats being presented in complete total flaccid paralysis within 72 hours after getting “all their shots”. Extensive diagnostics had been done on both animals by their regular vet before being presented to me and in both cases the owner’s were told that nothing was apparently wrong with their pet and that the vaccines couldn’t be at fault!!! Many times every month I hear new clients complain about their pet being sick for up to 2 weeks after receiving multiple vaccines at once. I think our own pets are telling us something and maybe we should listen to them.

The American Veterinary Medical Association now recommends all veterinarians develop a core of only necessary vaccines for their area and not to give all available vaccines. They also recommend that multiple vaccines not be given at the same time. The American Animal Hospital Association is now saying all dogs need only a core of rabies, distemper, parvovirus and adenovirus type 2 and that they only need to be given once every three years. Other vaccines are considered optional according to circumstances. Vaccines such as giardia and coronovirus are recommended not to be used at all.

The Iowa Animal Welfare Act as it stands now is grossly out of date. It requires annual vaccines for boarding kennels and grooming facilities. It even lists Corona virus as a required vaccine. Corona is only an infrequent problem in very young puppies. Adult dogs will not even contract the disease in natural exposure and I consider vaccinating adults for it to be malpractice. Contact your representative in the Iowa Legislature and insist on a review on these requirements. I would be more than happy to help present the current research to the lawmakers.

1. Kirk’s Current Veterinary Therapy, Vol. XI, page 205
2. Colorado State University’s Small Animal Vaccination Protocol, http://www.cvmbs.colostate.edu/vth/savp2.html
3. Vaccine-Induced Autoimmunity in the Dog, Harm Hogenesch, Juan Azcona-Olivera, Cathatine Scott-Moncrieff, Paul W. Snyder, and Larry T. Glickman, Departments of Veterinary Pathobiology and Veterinary Clinical Sciences, Purdue University, West Lafayette, Indiana 47907
4. Considerations in Designing Effective and Safe Vaccination Programs for Dogs, R. D. Schultz, Department of Pathobiological Sciences, School of Veterinary Medicine, University of Wisconsin-Madison, Wisconsin.