Rabies vaccine increases antibodies, study shows

West Lafayette, Ind.-A popular rabies vaccine increases thyroid antibodies in dogs, but whether those antibodies cause hypothyroidism is largely unknown.

That's the gist of a six-year study conducted by Purdue University researchersin the latest attempt to prove vaccinations play a role in the developmentof autoimmune disease and cancer.

Published in the Aug. 15 issue of the Journal of the American VeterinaryMedical Association, the study monitors the effect of IMRAB-3, the mostwidely used rabies vaccine in the United States, on dogs. Although the datastops short of supporting co-author Dr. Larry Glickman's theory that rabiesvaccines foster hypothyroid-triggering antibodies, "it's one step closer,"he says.

"There's a whole host of autoimmune diseases out there," Glickmansays. "Some think they're caused by environmental factors, maybe viruses.We think it's immunizations."

The Centers for Disease Control and Prevention report 7,500 U.S. rabiescases each year, a fraction of which are companion animal.

"Very effective, very safe"

Some veterinarians have been questioning annual vaccination standardssince the early 1990s when increased rates of cancer were reported at felinevaccination sites. It was the first hard evidence that vaccines could havebad side effects, Glickman says. "It got us thinking, do we reallyneed to use vaccines so often?"

In the case of IMRAB-3, the answer is yes, say veterinary scientistsat Merial, the pharmaceutical's manufacturer.

"This is an interesting article, but it means nothing clinically,"says Dr. Zack Mills, Merial's director of vaccines and therapeutic pharmaceuticals."None of the dogs developed any thyroid disease as a result of IMRAB-3.

"What I don't want to see happen is everyone running around sayingthat this vaccine causes thyroid problems in dogs. IMRAB is very effectiveand very safe."

A call for more research

Even though he lacks proof, Glickman disagrees. He says more researchneeds to be done on all vaccines, not just IMRAB-3. But that's not likelyto happen. He says funding is lacking and pharmaceutical companies aren'tquick to support such scientific endeavors.

For example, isolating and researching the study's 20 Beagles from newbornsto 6 years of age ran about $500,000. The John and Winifred Hayward Foundation,a philanthropic group, funded the research, wanting to make the vaccine-diseaseassociation in animals before studying a human correlation.

And since the federal regulating agencies overseeing vaccines don't forcepharmaceutical companies to study their products' long-term effects or howlong they last, further research dollars are less likely.

Mills explains: "We can invest money to see how long an old vaccineof ours works, or we can fund the improvement of vaccines, making them saferand cleaner.

"We are constantly looking for ways to improve our products. Thereare always risks and benefits associated with vaccines as (vaccinating isa) medical procedure. But we don't want to be tied up researching old vaccines.If that happens, we won't be creating new drugs."