In previous discussions of vaccination recommendations, I have referenced several clinical guidelines that review the existing evidence and provide recommendations for vaccination. The American Animal Hospital Association (AAHA) and American Association of Feline Practitioners (AAFP) guidelines are quite extensive and useful documents in making decisions about vaccination. AAHA guidelines are, unfortunately, usually prepared by small groups of experts with little transparency, and they are not always a model of evidence-based guideline development (for a great model, see the RECOVER guidelines for small animal CPR). That said, the vaccination guidelines do a good job of summarizing the complex and sometimes contradictory evidence and making reasonable recommendations.
AAHA has update the canine vaccination guidelines, and has presented them in a new form. The 2017 AAHA Canine Vaccination Guidelines are now primarily an online document divided into sections that make finding the answer to specific vaccination questions quite easy. In terms of providing a summary of existing vaccine science and giving a general overview of the issues, the web-based format is clunky and harder to use than a traditional journal article. But in terms of giving direct answers to questions vets and dog owners typically have about when and how to use specific vaccines, the format works well.
The new guidelines also add detail to subjects only lightly discussed in the previous version, including the use of antibody titers to guide vaccination and how to handle animals with uncertain vaccine histories or overdue for boosters of vaccines given previously.
There is nothing revolutionary or earth-shattering in the new guidelines, and they will undoubtedly not satisfy the concerns of those with deep anxieties or objections to routine vaccination practices. The recommendations are very similar to previous versions, and there will be few changes for those of us who have been following these guidelines in the past. Thorny questions like how often, or if, boosters of core vaccines should be given are not always directly answered.
The previous guidelines summarized the evidence that, for example, vaccination for canine parvovirus (CPV) and canine distemper (CDV) should provide immunity for a minimum of three years and likely protects most dogs for at least 5-7 years and possibly longer (when given properly as a series to puppies with a booster at about one year). The currently guidelines recommend intervals for these vaccines of “three years or longer”, which leaves the exact interval to the discretion of vets in practice. This makes sense in many ways, since the risks and benefits of vaccination for individual animals depends on exposure risk, lifestyle, health, medical treatment, and many other variables. Ultimately, there is no single right answer for every dog.
Unfortunately, it is easier for most vets to choose an arbitrary recommendation to make for all their patients. Right now, many choose three year intervals for these vaccinations because that number was specifically suggested in the AAHA guidelines. When I have suggested longer intervals might be appropriate, many of my colleagues are understandably wary of deviating from what all the major veterinary schools and most other practices are doing for fear of being blamed for any failure of protection that might occur. And, of course, none of this will satisfy those who think little or no vaccination is necessary at all.
Despite the inevitable compromises and limitations in the evidence, however, the AAHA guidelines are an excellent resource for vets and dog owners wishing to make rational, science-based decisions about how best to protect dogs from vaccine-preventable disease.
Revaccination Recommendations
The new labels will no longer carry a routine, default recommendation for annual revaccination. Revaccination statements on the new labels will be based upon data. Where there is not data indicating a specific revaccination interval, the label will carry a statement to indicate that a revaccination interval has not been established and a veterinarian should be consulted.
1 Single Label Claims for Veterinary Biologic Products, 80 Fed. Reg. 39669 (2015)
2 Packaging and Labeling, 81 Fed. Reg. 59427 (2016)>>>>>>
cool,
Nice to see the federal government no longer is going to default to pet vaccine health fraud labels.
Maybe the required by law CE pet vaccine speakers will stop telling vets they need to vaccinate annually for something if there are no labels on the vaccine bottles recommending we do so.
“There is no known value in administering the IN vaccine bi-annually (every 6 mo).”>>>
I think this quote is a giggle. Maybe AAHA will tell us the known value in administering the IN vaccine annually in their next aaha vaccine guideline up date.
Some recommendations for cats?
My cats don’t go out so until now they are pretty healthy.
Here are the most recent guidelines from the American Association of Feline Practitioners.
B bronchiseptica risk should be reassessed for all cats annually and the vaccine administered, if deemed necessary.>>>>>>
Why not do a “deem necessary” and vaccinate reassesment every 6 months? How often is a vaccine risk assessment needed in human medicine?
Would you recommend CAV-1 vaccine or CAV-2 as part of the core? Also, for a 1.5-year-old Bichon that did not receive any vaccines as a pup, would he need 1 shot or a series of shots? Thank you!
I do recommend CAV-2 as a core vaccine, in accordance with the latest guidelines. CAV-1 is not generally used in vaccines as it has a higher risk of adverse events, and CAV-2 will provide protective immunity against CAV-1.
As for the number of vaccinations needed if no initial series was given, it will depend on the type of vaccine and the risk of exposure for the individual dog. generally, modified live vaccines provide adeqaete immunity with one vaccination, whereas killed vaccines require a series, though there are exceptions (e.g. rabies, which is a killed vaccine that provides sufficient immunity after one vaccination). You will need to discuss the details of your pet’s needs with your veterinarian.
Thank you for your response!
The one question asked a lot about vaccinations is why do pets need boosters but we humans dont ? a science based answer to this would be great .
fully immunized humans get some boosters
https://www.cdc.gov/vaccines/pubs/pinkbook/tetanus.html
From this website it looks like tetanus can last your life time but the government wants you to get a booster every 10 years. I am not sure if the government has good prospective randomized trials to support the tetanus booster every 10 years. The government may be promoting preventative care with no RCT to support by using the parachute argument you do not need a good randomized controlled trial for everything.
in case you do not want to read the entire page here is the part i referred to.
“Efficacy of the toxoid has never been studied in a vaccine trial. It can be inferred from protective antitoxin levels that a complete tetanus toxoid series has a clinical efficacy of virtually 100%; cases of tetanus occurring in fully immunized persons whose last dose was within the last 10 years are extremely rare.
Antitoxin levels decrease with time. While some persons may be protected for life, by 10 years after the last dose, most persons have antitoxin levels that only approach the minimal protective level. As a result, routine boosters are recommended every 10 years.”
Thank you , in the dog world the anti vaxers are using the idea the humans get vaccinated as children , and never again , but dogs need regular boosters .
but dogs need regular boosters>>>> only if you accept the argument you do not need a good randomized controlled trial for every traditional medical practice promoted in the market place. I would like to see pet vaccine makers be made to prove regular boosters are needed before the USDA allows the manufactures to put a give every year label on the vaccine label.
A couple of points:
1. It is not true that humans don’t need boosters. Here are the CDC recommendations for vaccination in adults. The duration of immunity depends on the disease, the vaccine, and the patient. Humans get influenza annually, due to changes in the virus. Tetanus is every 10 years. Rabies for people with significant exposure risk is determined by titers. 1-2 doses of the MMR after 18 years of age is not recommended since it has been shown that childhood immunization is not always lifelong. There are plenty of other examples.
2. The need for boosters in animals also depends on the disease, the vaccine, and the individual. Often, unfortunately, we have less data that exists for humans to help determine the duration of immunity since public health agencies don’t make a point of studying this over decades the way they do for people. Many core vaccines were initially tested only for 1 year duration, so boosters were given annually. AAHA now recommends boosters anywhere from annually to every 7 years, depending on the vaccine and the strength of the data available for determining duration of immunity. So the interval for boosters is always changing as we gather more evidence.
We have to be careful about oversimplifying issues around vaccination and ignoring the important differences between various vaccines and diseases. We also have to recognize that adverse effects of vaccines are not as serious or common as often claimed, and when balancing these against the benefits and the risk of not vaccinating often enough, we must frequently make decisions with imperfect information. As long as we continue to study these questons and update our practices as justified by the evidence, this is how medicine should work.
The article you quote, Art, states that surveys of antitoxin levels suggest most people are approaching the borderline between protective and non-protective levels by 10 years, and some may be unprotected before 10 years. This is not an RCT, but it is a rational strategy for deciding when to give the vaccine. There are plenty of reasons why an RCT isn’t going to be done on this subject, primary among them the fact that it would be unethical to expose people to challenge testing and deliberately give them tetanus to determine the protective fraction at particular time points, which is how such a trial typically works in animals. RCTs are the best type of evidence in many cases, but they are not appropriate for everything, and we can’t just ignore every other kind of evidence when RCTs don’t exist or cannot properly be done.
“While some persons may be protected for life, by 10 years after the last dose, most persons have antitoxin levels that only approach the minimal protective level. As a result, routine boosters are recommended every 10 years. In a small percentage of individuals, antitoxin levels fall below the minimal protective level before 10 years have elapsed.”
What would be your recommendation for the leptospirosis vaccine, for a dog who might be exposed to it? Is there evidence that annual boosters are necessary, as indicated in the AAHA guidelines?
If there is a risk of exposure, then the vaccine has been shown to be effective and has minimal risk, so I would recommend it. There is strong evidence of protection at one year. We know that antibody levels are often very low after 1 year, but we also know that antibody levels are not a reliable guide to immunity for this disease (1). The duration of immunity is not consistent or predictable with this disease beyond one year, so I would recommend following the guidelines in boosting annually if there is a risk of exposure.
lepto vaccine DOI promoted is all over the place both in human and vet medicine. This should be a red flag that we may not know if the vaccine really works. We were told in the old days to vaccinate for lepto every six months. Would vaccinating every three months or every three years for lepto be a better idea?
There are just a few countries that have human lepto vaccines. The only prospective randomized field study I can remember seeing was out of cuba. The human lepto vaccine was compared to a homeopathic vaccine. Water in a bottle worked just as well as the human cuban lepto vaccine in the study.
Lepto bacteria grown in the lab express different antigenic cell membrane proteins than those lepto cell membranes expressed in natural infections.(see below) It is important that we know if lepto vaccine efficacy shown in USDA trials results because of antibodies produced as a result of exposure to surface antigens that are expressed in cultured lepto but not lepto organisms producing natural clinical disease. Lepto vaccine needs to be proven therapy for host derived organisms since our patients are not going to even be exposed to cultivated lepto. There are no FDA approved human lepto vaccinations and no evidence that I am aware of that any lepto vaccination is efficacious against host derived organsisms. I suspect all we may be doing is vaccinating our patients to protect against a lab created antigen and convinced our clients to beleive their pets were protected agaist host derived lepto organisms.
Review Article
Spirochaetal lipoproteins and pathogenesis
David A. Haake1
Changes in lipoprotein expression have also been found to occur in Leptospira species. Immunohistochemistry was used to evaluate whether lipoproteins expressed by cultivated Leptospira species were also expressed during infection. These experiments took advantage of the fact that in kidneys of infected animals, pathogenic Leptospira species are found in high numbers within proximal renal tubules. Experiments revealed expression of a number of membrane antigens, including leptospiral LPS, the OmpL1 porin and the lipoproteins LipL32 and LipL41 (Barnett et al., 1999 ; Haake et al., 2000 ). However, a third lipoprotein, LipL36, which is expressed at high levels in cultivated organisms, was undetectable by immunohistochemistry (Barnett et al., 1999 ). These observations were validated by examination of the antibody response in animals experimentally infected with host-derived organisms (Barnett et al., 1999 ). Research is ongoing in our laboratory to determine the signals that regulate differential expression of LipL36.
The theoretical argument that vaccines may not be effective because of differences in expression of surface proteins byt the bacterium during infection and during cultivation is a pretty weak argument considering the significant decline in canine leptospirosis cases seen when vaccines with relevant serovars are introduced into previously unvaccinated populations. The vaccines have worked to reduce natural infection, and while we cannot predict duration of immunity very well based on antibody titers, that is a long way from saying we don’t know if the vaccines are effective or not. Challenge studies are strong evidence, and they are consistent with the epidemiologic evidence, so it is far more likely that the vaccines are effective when they contain the locally relevant serovars.
Its been over ten years so the Cochrane Controlled Clinical Trials Database may have been updated but its behind a paywall now. There are about 250 listed pathogenic lepto serovars identified so far and I think about 10 more serovars every year. The serovars in the lepto vaccines do not cross protect. I suspect for a lepto vaccine to possibly work you would need to reformulate it yearly like human flu vaccine depending what lepto seravar was circulating around the world or better yet your local community at the time. A flu vaccine for humans is not going to work if you pick 4 influenza virus that may have been a problem twenty years ago and booster that every year. Bottom line from the systemic review below “Any interventions for leptospirosis, such as prevention and treatment remains unclear for guidelines and practice.” I even have a systemic review somewhere from years ago that penicillin may cause more harm than good for lepto treatment. I will post that if I can find it.
SYSTEMIC REVIEWS ON LEPTOSPIROSIS IN HUMANS
Guidugli F, Castro AA, Atallah AN
Federal University of Sao Paulo, SP, Brazil.
[Medline record in process]
OBJECTIVES: To find the existing clinical evidence on interventions for leptospirosis. The objective is to evaluate the effectiveness and safety of any intervention on leptospirosis through systematic reviews of randomized controlled trials (RCTs). DATA SOURCE: The sources of studies used (where there were no limitations concerning language, date, or other restrictions) were: EMBASE, LILACS, MEDLINE, the Cochrane Controlled Clinical Trials Database, and the Cochrane Hepato-Biliary Group Randomized Trials register. SELECTION OF STUDIES: Type of Study: All systematic reviews of randomized controlled trials. Participants: patients with clinical and/or laboratorial diagnosis of leptospirosis, and subjects potencially exposed to leptospirosis as defined by the authors Interventions: any intervention for leptospirosis (as antibiotics or vaccines for prevention or treatment). DATA COLLECTION: The assessment will be independently made by the reviewers and cross-checked. The external validity was assessed by analysis of: studies, interventions, and outcomes. DATA SYNTHESIS: Located 163 studies using the search strategy described above, at the electronic databases above. Only 2 hits were selected, which are protocols of systematic reviews of Cochrane Collaboration, and not full reviews. One of the protocols evaluates antibiotics for treatment, and the other evaluates antibiotics for prevention of leptospirosis. CONCLUSIONS: There were not complete systematic reviews on interventions for leptospirosis. Any interventions for leptospirosis, such as prevention and treatment remains unclear for guidelines and practice.
I remembered it wrong. the evidence below “suggest” that penicillin “may” cause more good than harm. Not sure about injections of Penicillin/streptomycin we used in vet school. At least the injections reduced the lepto count in the urine.
see
Antibiotics for treating leptospirosis
Guidugli F, Castro AA, Atallah AN Guidugli F, Castro AA, Atallah AN. Antibiotics for treating leptospirosis (Cochrane Review). In: The Cochrane Library, Issue 2, 2000. Oxford: Update Software., ,
ISBN: 1464-780X
This is a regularly updated Cochrane review. Please contact the author of the review using the contact details provided if you have comments or criticisms.The complete review is available in The Cochrane Library. For information on The Cochrane Library, contact Update Software Ltd, Summertown Pavilion, Middle Way, Summertown, Oxford OX2 7LG, England. Tel: +44 1865 513902, Fax: +44 1865 516918, Email: info@update.co.uk
Author’s objective
Background:
Leptospirosis is a parasitic disease transmitted by animals. Severe leptospirosis may result in hospitalisation and about five per cent of the patients die. In clinical practice, penicillin is widely used for treating leptospirosis.
Objectives:
To evaluate the effectiveness and safety of antibiotics versus placebo or other antibiotic regimens in treating leptospirosis. We addressed the following clinical questions: a) Are treatment regimens with antibiotics more efficient than placebo for leptospirosis? b) Are treatment regimens with antibiotics safe when compared to placebo for leptospirosis? c) Which antibiotic regimen is the most efficient and safest in treating leptospirosis?
Search strategy:
Electronic searches and searches of the identified articles were combined.
Selection criteria:
STUDIES: Randomised clinical trials in which antibiotics were used as treatment for leptospirosis. Language, date, or other restrictions were not applied. PARTICIPANTS: Patients with clinical manifestations of leptospirosis. INTERVENTIONS: Any antibiotic regimen compared with a control group (placeboor another antibiotic regimen).
Data collection and analysis:
Data and methodological quality of each trial were independently extracted and assessed by two reviewers. The random effects model was used irrespective of significant statistical heterogeneity.
Main results:
Three trials met inclusion criteria. Allocation concealment and double blind methods were not clearly described in two. Of the patients enrolled, 75 were treated with placebo and 75 with antibiotics: 61 (81.3%) penicillin and 14 (18.6%) doxycycline. The patients assigned to antibiotics compared to placebo showed: a) Mortality: 1% (1/75) versus 4% (3/75); risk difference -2%, 95% confidence interval -8% to 4%. b) Duration of hospital stay (days): weighted mean difference 0.30, 95% confidence interval -1.26 to 1.86. c) Prolonged hospital stay (> seven days): 30% (7/23) versus 74% (14/19); risk difference -43%, 95% confidence interval -70% to -16%. Number needed-to-treat 3, 95% confidence interval 2 to 7. d) Period of disappearance of fever (days): weighted mean difference -4.04, 95% confidence interval -8.65 to 0.58. e) Leptospiruria: 5% (4/75) versus 40% (30/75); risk difference -46%, 95% confidence interval -88% to -3%. Number needed-to-treat 2, 95% confidence interval 1 to 33.
Reviewer’s conclusions:
Antibiotic regimens for treatment of leptospirosis is a form of care for which the evidence is insufficient to provide clear guidelines for practice. The randomised trials suggest that antibiotics could be a useful treatment for leptospirosis. Because of the questionable quality of two of the three trials, the indication for general use of antibiotics is uncertain. However, the evidence suggest that penicillin may cause more good than harm.
*****
I’m concerned about dosing for rabies vaccine… is given bus weight dosage or do all dogs receive the same dose, no matter what size they are??? We have an 11 week old miniature schnauzer and we are concerned about the increased chance of an immunological diagnosis being brought about by giving our puppy the rabies vaccine… also we would like to know if all canine vaccines are preserved with thimerisol/mercury based preservative… I have become very sensitive to all vaccines preserved with thimerisol, this preservative was in the flu and tine tests that I had received and each time I received them I became increasingly ill, to the point I had to refuse the vaccines and tests if they contained it… ‘‘this preservative brought on a dramatic inflammatory response to the vaccine of which I become extremely ill and can no longer work in as an RN… perhaps dogs too, can have bad reactions toward thimerisol and developed dramatic exacerbations of inflammatory response to to vaccines containing thimerisol??? I know that with in the past ten years, thimerisol has been removed from vaccines given to humans maybe they should remove it from vaccines given to our fury friends too!!! What do you think???
I have a question about the bivalent canine influenza vaccine: the AAHA guideline is to booster yearly after the initial 2-dose series, but if the vaccine doesn’t change yearly the way human influenza vaccines do, is it actually necessary? My understanding for the reason we get a flu shot every year is because the prevalent virus strains change year to year, and thus the flu vaccine is different every year to match the most recent virus prediction. Does Merck (manufacturer of the bivalent H3N2/H3N8 vaccine my dog got this year) update the dog vaccine yearly for mutations? Or does the vaccine not provide long-term immunity for dogs? I live in an as-yet-not-endemic canine influenza area (BC, Canada), but canine influenza is always potentially only 1 improperly-quarantined foreign rescue dog away.
The virus does not mutate as it does in humans because there is far less international travel among dogs, which is the main feature leading to circulation of different seasonal flu strains in humans. There is some antigenic drift, so strains can change, but the process seems to be very slow.
The company that makes the vaccine recommends a annual booster based on the limited testing of the vaccine showing protective immunity only for 1 year. It may be that further research will show a longer duration of immunity (this is highly variable base don the disease, type of vaccine, etc.), but it is a killed vaccine and these typically have much shorter duration of immunity than modified live vaccines.
In the good old days the last puppy vaccine used to fully immunize was called the final adult shot. When humans started getting reformulated flu vaccines every year the pet vaccine government regulators allowed pet vaccine makers to put a give every year label on the vaccine bottles with out any prospective randomized controlled trial the practice has efficacy. State boards are now starting to require pets be seen every year to maintain a dr/Patient/client relationship to support “annuals”. While human doctors struggle to practice evidence based preventive care the veterinary profession is now required by non- FDA controlled law to base their practice astrology. I must base pet medical care on how long it takes the earth to go around the sun rather than medical science that the FDA requires. The USDA practicing astrology is also responsible for the sale of most antibiotics sold in the USA being used in animals. Animals we eat that are not sick or diseased. The usda needs shut down and it’s job given to other government agencies more consumer and evidence based medicine friendly.
as you see from consumers union the usda creates its approved labels from behind closed doors. Not only for food we eat related to antibiotics but the pet vaccine usda vaccine labels approved as a secret sauce
Search
What should the government do to regulate antibiotics?
Consumers Union recommends government take the following actions to end the overuse of antibiotics in livestock production.
Congress
While consumer pressure may be a more immediate catalyst for moving livestock producers away from using antibiotics, a long-term and more permanent legislative or regulatory solution would be ideal. A bill that has been introduced in Congress, the Preservation of Antibiotics for Medical Treatment Act (PAMTA), would prohibit the use of medically important antibiotics in livestock production (except when treating sick animals) and thereby protect the efficacy of these drugs for human use. In light of the public health implications of losing the efficacy of these critical drugs for people, Congress should pass this legislation immediately.
Food and Drug Administration (FDA)
The FDA recognized decades ago the inherent problem with the overuse of antibiotics in livestock production. After years of inaction, the agency in early 2012 issued new guidelines for the livestock and pharmaceutical industries
requesting the “judicious use” of antibiotics in animals. However, these guidelines are merely voluntary, and while they attempt to discourage the use of antibiotics for growth promotion in animals, they continue to support the widespread
use of these drugs for disease prevention (albeit under the guidance of a veterinarian, which is a step in the right direction). The FDA states it will review these guidelines again in three years to gauge progress and take additional action if needed. The FDA should strengthen these guidelines and establish a mandatory ban on the use of antibiotics in animal production except to treat sick animals.
U.S. Department of Agriculture (USDA)
Consumers who want to buy meat raised without antibiotics should be able to feel secure that the labels on those products are meaningful (i.e. that there is a definition for them) and that their truthfulness is verified by someone. Our
shoppers found several instances of labels that could mislead consumers to believe they were buying meat from animals that were not given antibiotics, when in fact that is not necessarily the case. And although the USDA is supposed to
approve all labels on meat and poultry packages prior to use, our shoppers and researchers found several unapproved labels in the marketplace.
The USDA should improve its supervision of labels related to antibiotic use in several ways:
The USDA/FSIS currently conducts its reviews behind closed doors and does not disclose what specific labels it has authorized or which companies have been authorized to use them. The USDA should post on its website all authorized labels, the products they are authorized for, and the label definition, to help consumers understand the labels.
The USDA should establish one approved phrasing for such labels, such as “no antibiotics ever used,” and restrict all labels to that usage. That would significantly reduce consumer confusion.
The USDA should establish a formal standard defining this label (the USDA indicated to Consumer Reports that it does not allow use of ionophores and prohibits antibiotic use at any stage of an animal’s life, if meat is to carry a “no antibiotics” label, but the full definition is not published on its website). This would help both companies and consumers understand label requirements and facilitate better enforcement.
The USDA should check up on “no antibiotics” labels to verify their truthfulness, and take action against labels that do not conform to its established definitions.
Consumers Union (CU) is an expert, independent, nonprofit organization whose mission is to work for a fair, just and safe marketplace for all consumers and to empower consumers to protect themselves.
© 2018 Consumers Union.
Calling it Astrology is BS, Art. While there are never going to be long-term prospecive challenge studies comparing individuals vaccinated at different intervals in terms of duration f immunity, the fact is there is a good bit of research data showing that different vaccines lead to different duration of protection for different proportions of the population depending on many variables, some we don’t understand. Annual boosters are clearly not appropriate for some vaccines (e.g. DAPP, RV), they probably are for others (e.g. lepto, bordatella), and you don’t have any better insight into how often to vaccinate than anyone else. The problem of one unjustified interval (e.g. annual) isn’t solved by this kind of silly hyperbole or by the widespread practice of making up other equally irrational plans (e.g. Jean Dodds).
When a preventive treatment works it can be shown to work. When the government is practicing health fraud you are supposed to stay as far away as possible. I suspect that is why Pfizer got out of the animal pharmacy business.
Veterinarians Question Vaccination Procedures
Vaccinations can have adverse effects, studies show
By Rhonda L. Rundle
THE WALL STREET JOURNAL
July 31
After receiving a reminder in the mail from his veterinarian, Jim Schwartz
took his 11-year-old poodle, Moolah, for her annual rabies shot. A few
weeks later she fell ill and was diagnosed with an autoimmune disease. As
her suffering worsened, Mr. Schwartz put her down.
THERE’S NO PROOF that the rabies shot killed Moolah and Mr. Schwartz didn’t
immediately suspect any link. But when the retired financial planner
learned that some veterinarians are vaccinating pets less frequently
because of possible fatal side effects, he was furious. “No dog should have
to go through what Moolah did,” he says.
Evidence is building that annual vaccination of dogs and
cats performed for diseases such as rabies, distemper and parvovirus may
not be necessary and could even be harmful. Vaccines licensed by the U.S.
Department of Agriculture are tested to ensure they protect pets against
disease, usually for one year. But the tests don’t detect long-term side
effects, or measure the duration of a vaccine’s effectiveness. Recent and
continuing studies at several universities suggest that protection from
vaccines may last for years, which would make annual shots for some
diseases a waste of money at the very least.
Fears of vaccine-induced diseases date back more than 40 years. But a sharp
increase during the past decade in cancerous tumors among cats, between the
shoulder blades where vaccines typically are injected, has spurred studies.
Some have found a higher-than-expected incidence of side effects. “We see
health problems in dogs for which we have no explanation. The classic one
is autoimmune disease,” says Larry Glickman, professor of epidemiology at
Purdue University’s School of Veterinary Medicine in West Lafayette, Ind.,
who is studying possible links with vaccinations. “We see an epidemic of
hyperthyroidism in cats today, and we suspect that these are happening
because we’re over-vaccinating our pets.”
ACCUMULATIONS ARE THE DANGER
Dr. Glickman and his colleagues theorize that repeated vaccination
causes dogs to produce antibodies against their own tissue. The antibodies
are caused by contaminants in the vaccine introduced in the manufacturing
process. While the amounts are minuscule, they gradually accumulate with
repeated vaccinations over the years. But Dr. Glickman cautions that more
research is needed before a clear link can be established between antibody
levels and autoimmune disease.
Vaccination recommendations for cats and dogs vary around the country. Most
states require rabies vaccinations every three years, while a handful of
states as well as some individual cities and counties have mandated
annual shots due to local problems with rabies in wild animals. Some other
vaccinations are given only when a pet’s lifestyle or environment exposes
it to a particular risk, such as Lyme disease.
Pet diseases other than rabies aren’t a threat to people, thus vaccinations
aren’t required by law. But veterinarians and vaccine makers have
traditionally recommended annual booster shots against potentially fatal
diseases such as distemper and parvovirus in dogs and herpesvirus in cats.
In a policy statement last year, the American Veterinary Medical
Association acknowledged that the practice of annual vaccinations is based
on “historical precedent” and “not on scientific data.”
The emerging evidence of health risks is prompting some vets to
change their practices. “We’re now doing 40% less vaccinations than five
years ago,” says Kathleen Neuhoff, a veterinarian in Mishawaka, Ind., and
president of the American Animal Hospital Association, Lakewood, Colo.
FINANCIAL REASONS?
“My own pets are vaccinated once or twice as pups and kittens, then
never again except for rabies,” Ronald D. Schultz, chairman of the
University of Wisconsin’s Department of Pathobiological Sciences, wrote in
the March 1998 issue of Veterinary Medicine.
Some critics of annual shots accuse some vets of ignoring research
about vaccine risks for financial reasons. “Vets are afraid they will go
broke” without regular vaccines, which account for about 20% of their
practice income, says Bob Rogers, a Spring, Texas, veterinarian and
outspoken critic of current practices.
Other vets deny that financial motives are involved. (“No one who
is motivated by money would ever become a veterinarian,” Dr. Neuhoff says.)
“The concern is that if we move too quickly to decrease vaccine frequency
across the board, we may be opening the door for some animals to become
infected when we could have prevented the problem,” says Todd R. Tams,
chief medical officer of VCA Antech Inc.,in Los Angeles, the nation’s
largest owner of veterinary hospitals.”
No one truly knows how long protection from vaccines lasts. Vaccine
makers say that proving their duration would be expensive and would require
large numbers of animals to be isolated for years.
One company, Pfizer Inc., decided to test its one-year rabies
vaccine on live animals and discovered it lasted for at least three years.
It sells the identical formula simply packaged under different
labels Defensor 1 and Defensor 3 to satisfy different state vaccination
requirements.
We agree that annual rabies and DAPP vaccination is unnecessary, and I’ve already said that many times. Still doesn’t mean annual boosters aren’t sometimes necessary for other vaccines depending on all the factors I’ve referred to and which you keep ignoring. As for the risks, the notion of autoimmunity secondary to vaccination is pretty tenuous, and not much evidence supports it.