Guest guest Posted November 27, 2004 Report Share Posted November 27, 2004 PROGRESS REPORT: Effects Of Vaccination On The Endocrine And Immune Systems of Dogs, Phase II Purdue University, November 1, 1999 Drs. Harm HogenEsch and Larry T. Glickman > > Concern has been growing among owners, breeders, and veterinarians that current vaccines cause immune-mediated diseases in dogs. Vaccination is highly effective in preventing infectious disease, but the safety of many vaccines and the frequency of their administration are being questioned. The Vaccine Research Group at the Purdue University School of Veterinary Medicine has been conducting several studies to address these issues. In one such study, we are trying to determine if current vaccines cause changes in the immune system of the dog that will eventually result in life-threatening immune mediated diseases. The Beagle being used in this study were bred by us and then vaccinated following a typical schedule used for pet dogs. These Beagles have been closely followed for three years with blood and other tests performed at regular intervals. > > To date, routine vaccination of these Beagles has not caused any overt signs of clinical disease. However, the blood of all the vaccinated dogs contains significantly elevated concentrations of antibodies directed against proteins that are present in commercial vaccines as contaminants of the production process. None of the unvaccinated control dogs has had a similar increase in these antibodies. These proteins are typically of bovine origin since fetal calf serum is used to grow the viruses for vaccine production. The close similarity in structure of the bovine proteins to dog proteins results in a situation whereby the antibodies produced by the vaccinated dogs may cross-react with dog tissue proteins in a process similar to autoimmunity. Experiments in other animal species suggest that these autoantibodies might eventually cause diseases in the vaccinated animals, but these Beagle dogs will need to be followed longer to determine if this is the case. In addition, the pattern of individual responses of the immune system to vaccination in this study suggests a possible genetic predisposition to autoimmunity. > > The study described above is unique in that it attempts to determine if vaccinations that dogs routinely receive throughout their life have a cumulative adverse effect. The only way this is possible is under experimental conditions where one group of dogs remains unvaccinated. The vaccine studies we are conducting both in Beagles and in pet dogs under natural conditions are designed to answer the question: " Does vaccination play a role in autoimmunity, how safe are currently used vaccines, and how often should these vaccines be administered? > > Source: http://www.doglogic.com/purduevaccinestudy.htm > > > The Akita Club of America also email interviewed Larry Glickman, VDM, PhD > > Q: Dr. Glickman, > > How long do you think the current 1 year ImRab vaccine is actually capable of providing immunity to an animal? > > A: If this is the same vaccine as the 3 year ImRab product, then it should provide a protective titer for 3 years. However, since the 1 year ImRab vaccine label says to revaccinate yearly, the dog is only considered to be protected against rabies for 1 year by public health officials. Therefore, if it is exposed to a rabid animal more than 1 year after vaccination, it will be considered as unvaccinated. This means it will either have to be euthanized or placed in strict isolation for 6 months. One should not confuse duration of immunity with legal requirements, since they are often in conflict. That is, there is no scientific basis when a state law requires yearly vaccination with a vaccine that should provide protection for 3 years. > > Q: As a follow-up, many people are now titering: In your opinion, is this a valid method of insuring immunity? > > A: Public health officials do not consider this to be a valid method of insuring immunity when it comes to rabies in dogs. Therefore, it means little what I think. This is a different situation from measuring a titer for distemper and parvovirus to determine if a dog needs a yearly booster. > > Q: At what age do you feel, should it be available and legal within their region/country, should owners really prefer titering over vaccination as a means of insuring immunity in their Akita? Or should they at any age? > > A: Since rabies titers are not recognized as valid by public health officials and state law for measuring rabies immunity, it can never be recommended. > > In contrast for distemper and parvovirus, I recommend a series of immunizations as a puppy followed by a booster one year later. After that I recommend doing a titer every year to determine if another booster is needed. > > Q: Knowing how prone Akitas are genetically to autoimmune disease, what changes do you feel could be made to the current genre of vaccines to make them safer and more efficacious? > > A: First we need to do more studies to determine what vaccine factors are associated with adverse reactions. For some adverse reactions it may be the adjuvant in the vaccine while for others it may be contaminants in the vaccine that result from the use of calf serum during production. Based on our recent study, it looks like contaminants in some vaccines may be responsible for producing an autoimmune response which is enhanced each time the dog receives a booster vaccine. It is definitely possible to produce canine vaccines that have much lower levels of such contaminants or which are entirely contaminant free. This can be done by purification of the final product or by using tissue culture techniques that do not use calf serum as a source of nutrition for the cells. Another way to do this would be to produce vaccines using more advanced molecular methods such as recombinant technology or subunit vaccines. These approaches are used to produce many human vaccines, but it increases their cost. Veterinary vaccine companies are aware of this, but do not think dog owners will pay the added cost to produce a safer product. I think they are dead wrong and have told them so. > > Source: http://www.akitaclub.org/health/short_interview_with_dr.htm Quote Link to comment Share on other sites More sharing options...
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