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Booster jabs ‘unnecessary’ say vets

PET OWNERS are wasting millions of pounds each year on unnecessary booster vaccinations for dogs and cats, according to a number of vets who have ‘broken ranks’ against the traditional establishment view.

More than 30 vets have signed an open letter stating that many vaccines for life-threatening diseases last for many years and sometimes provide life-long immunity. This makes the annual boosters recommended by the manufacturers of vaccines unnecessary, they said, pointing to recent research.

But the vets' professional body, the BSAVA rejected the claims and warned that animals would suffer if their owners neglected regular jabs.

Many vets send letters each year to pet owners, reminding them to update their animals' vaccinations. A single booster injection can cost between anywhere between £20 and £40.

The letter, published in the Veterinary Times at the end of January, claims that the original vaccines for many diseases, including distemper, cat flu and parvovirus, last for many years.

Recent American research states "there is no proof that many of the yearly vaccinations are necessary and that protection in many instances may be life-long" – a completely different statement to the accepted annual booster line.

The vets’ letter said that some vaccines could cause "adverse events", including allergic reactions and cancer in cats. Vets stress the importance of vaccinations in preventing disease but called for boosters to be given every three years.

"Those who continue to give annual vaccinations in the light of the new evidence may well be acting contrary to the welfare of the animals committed to their care."

The vets added, however, that animals should be examined by vets every year in order to check on their welfare and general well-being.

The issue erupted at last week’s annual The British Small Animal Veterinary Association congress when reports of the letter in the national media caused a backlash from the BSAVA and vaccine manufacturers, who said they recommended yearly boosters because they could not prove that all animals received long-term immunity.

Vet David Sutton, a spokesman for Intervet, a veterinary drug manufacturer, said: "We base our recommendations on the science and the science tells us that we don't know how long immunity lasts in individual animals."


The BSAVA claimed the letter did not represent the views of most vets but that of a minority who had "sympathies with homeopathic medicine". Vaccination has provided the single greatest contribution to the health of our pets over recent decades.

"It is absolutely necessary if we want to prevent major epidemics of disease and the issue raised regarding over-vaccination of pets is simply not justified."

The BSAVA’s rather condescending dismissal of the vets who wrote the letter as ‘a minority who had sympathies with homeopathic medicine’ drew a strong rebuttal from one of the signatories. Indeed, the ‘homeopathic denunciation’ apparently only came about due to a media mailing from a leading vaccine manufacturer.

Chris Day, Hon Secretary of the British Association of Homeopathic Vets told OUR DOGS:

"We are first and foremost fully qualified veterinary surgeons with a full scientific training. So if there are any homeopathic leanings on top of that it is as a post-graduate endeavour.

"As one of the signatories to the letter, I feel I am in a position to point that this letter was not written by any of us as homeopathic vets nor did the BAHVS have a hand in the letter nor indeed are all the signatories homeopathic vets. "There is no scientific support for an annual booster system and in fact there is very little knowledge as to how often an animal should be boostered. David Sutton of Intervet is quoted in the media as saying ‘We base our case on science’ In fact, I shared a podium with him at a conference some years ago, where I said that there is no scientific support for annual boosting and he had to agree with me!"


Mr Day continued, saying: "There is current research from the USA showing more and more that annual boosting may be unwise in that it can reduce the immunity that is already present in animal’s body. It is very difficult to measure immunity because circulating antibodies are not the only factor involved in determining immunity. Indeed, the animal’s immune system probably has a memory enabling instant responses."

Another signatory to the letter, Vet Mark Elliott from The Centre for Integrated and Holistic Medicine further underlined the points raised by the vets who had signed the letter.

"We are totally Pro vaccination of puppies and young animals as appropriate, and by that we mean not too early, and not too often," said Mr Elliott."We are however, raising the question of whether animals older than 18 months actually need Boosters at all, especially as the evidence – taken from the recent American study - is already there to show that DHP immunity is for at least 7 years. Supporting this point is the fact that more than half the dogs, and even more of the Cats in the UK are greater than four years years behind in their boosters – and this information comes from an Intervet mailing. Yet where are the outbreaks? They just don’t happen, and this is likely to be because immunity is lifelong."

Mr Elliott added: "There has never been a study to show that annual vaccines are needed for any of the core vaccines in Cats or Dogs, there are plenty of studies to show the Duration of immunity is much longer than we are being told. Annual vaccination is an entirely historical precedent, and is not based on scientific data.

The American Veterinary Medical Association Council on Biologic and Therapeutic agents (2003) concluded there was no evidence to support the present annual recommendations.

The annual vaccination idea evolved when vaccines were pretty basic things, and there were lots of problems with getting appropriate durations of immunity. The reluctance in the Veterinary field to increase the interval between doses is lagging well behind the human field, where increases in vaccine interval are the norm as knowledge grows. Just one example is tetanus.


"We are facing a huge personal dilemma, as to question the manufacturers and to step out of their prescribed regimes leaves Vets exposed to personal risk. We are taught to follow protocols and considered "best practice", but the issue here is that the "best Practice" is being dictated by corporate interests, who do the research themselves, use the registration requirements to hide behind when dragging heels over this issue,

"Some manufacturers are trying to take a considered view in light of the new data, and we take our hat off to them for that initiative, but it is clearly not enough. Vets have been entrusted by parliament with the ethical responsibility for Animal Welfare, and we wanted to raise and expand on this debate, and take it back into the profession hands. We feel that the profession should go to vaccinations every 3 years NOW, and actively seek to take responsibility and the lead in this issue over the 2-year window of opportunity that would create. We also believe that the outcome of that issue will be that, booster vaccinations of animals will be shown to be unnecessary."

Responding to concerns expressed on the Radio 4’s Today programme, following an interview with BSAVA President, Freda Scott-Park on April 1st, the BSAVA and BVA issued the following statement regarding concerns about the over-vaccination of pets:

"First and foremost, vaccination has provided the single greatest contribution to the health of our pets over recent decades.

It is absolutely necessary if we want to prevent major epidemics of disease in this country and the issue raised regarding over-vaccination of pets is simply not justified.

Furthermore, as a highly trained and responsible professional, the veterinary surgeon has one priority, the health and welfare of animals that visit the practice. As such, the profession is duty bound to adhere to the best scientific information available to them at any given time.

The Veterinary Products Committee (VPC) - an independent, expert advisory group reporting to and advising both the licensing authority and the Government – has emphasised the safety and value of vaccination, and presented data on the extremely low prevalence of adverse reactions to these products in dogs and cats.

The VPC recommended that at this time there was insufficient justification to alter current data sheet recommendations for companion animal vaccines. To date the veterinary professional bodies have seen no justification to deviate from the VPC’s advice.

Veterinary surgeons must ensure that as many animals as possible are fully protected against killer diseases such as parvovirus, hepatitis, distemper and leptospirosis and that this protection is maintained throughout their life.

The fact remains that we still do not know enough about the true duration of immunity in individual animals but we do know enough to be able to say that not all vaccines necessarily provide lifelong protection.

The degree and duration of immunity can vary greatly between different individuals and many external factors also have to be taken into account. Without actually testing the immune status of the animal for every disease, one cannot know the level of immunity it possesses.

Whilst this testing is possible it incurs extra expense to the owner and may well serve only to demonstrate that the animal does indeed require a booster vaccination. We have no problem with discussing this issue with our clients.

If, after consultation with their veterinary surgeon, a client decides that they wish their pet to have less frequent vaccinations, we are happy for the vet to do so – this represents informed consent on the part of the owner – but we see no reason to vary from the legal requirement to follow data sheet recommendations otherwise.

Given the proven safety of companion animal vaccines and in the light of the best scientific evidence presented to practitioners in this country from independent bodies such as the VPC, we see no reason to change vaccination policy at this time.

Should new information appear that proves differently, then our profession will respond accordingly. "

The letter printed here from the vets to the editor of Veterinary Times was published in its January 26th issue and is reproduced with its kind permission:

Dear Sir

We, the undersigned, would like to bring to your attention our concerns in the light of recent new evidence regarding vaccination protocol.

The American Vet Med Assoc Committee report (2) this year states that "the one year revaccination recommendation frequently found on many vaccination labels is based on historical precedent, not scientific data".

In JAVMA in 1995 (1) Smith notes that "there is evidence that some vaccines provide immunity beyond one year. In fact according to research there is no proof that many of the yearly vaccinations are necessary and that protection in many instances may be life long" Also "Vaccination is a potent medical procedure with both benefits and risks for the patient." Further that "Revaccination of patients with sufficient immunity does not add measurably to their disease resistance, and may increase their risk of adverse post-vaccination events".

Finally, he states, "Adverse events may be associated with the antigen, adjuvant, carrier, preservative or combination thereof. Possible adverse events include failure to immunise, anaphylaxis, immunosuppression, autoimmune disorders, transient infections and/or long term infected carrier states".

The report of the American Animal Hospital Association Canine Vaccine Taskforce in JAAHA Vol 39 Mar/April 2003 (3) is also interesting reading:

"Current knowledge supports the statement that no vaccine is always safe, no vaccine is always protective and no vaccine is always indicated".

"Misunderstanding, misinformation and the conservative nature of our profession have largely slowed adoption of protocols advocating decreased frequency of vaccination".

"Immunological memory provides durations of immunity for core infectious diseases that far exceed the traditional recommendations for annual vaccination. This is supported by a growing body of veterinary information as well as well-developed epidemiological vigilance in human medicine that indicates immunity induced by vaccination is extremely long lasting and, in most cases, life-long".

Further, the evidence shows that the duration of immunity for Rabies vaccine, Canine Distemper vaccine, Canine Parvovirus vaccine, Feline Panleukopenia vaccine, Feline Rhinotracheitis and Feline Calicivirus, have all been demonstrated to be a minimum of 7 years, by serology for Rabies and challenge studies for all the others (4,5,6)

The veterinary surgeons below fully accept that no single achievement has had greater impact on the lives and well being of our patients, our clients, and our ability to prevent infectious diseases than the developments in animal vaccines.

We, however, fully support the recommendations and guidelines of the American Animal Hospitals Association Taskforce (3), to reduce vaccine protocols for dogs and cats such that booster vaccinations are only given every three years, and only for core vaccines unless otherwise scientifically justified.

We further suggest that the evidence currently available will soon lead to the following facts being accepted:

* The immune systems of dogs and cats mature fully at six months and any Modified Live Virus (MLV) vaccine given after that age produces immunity that is good for the life of that pet (7)

* If another MLV vaccine is given a year later the antibodies from the first vaccine neutralise the antigens from the subsequent so there is little or no effect. The pet is not "boosted", nor are more memory cells induced. (8,9)

* Not only are annual boosters for Canine Parvovirus and Distemper unnecessary, they subject the pet to potential risks of allergic reactions and immune mediated haemolytic anaemia.

* There is no scientific documentation to back up label claims for annual administration of MLV vaccines.

* Puppies and kittens receive antibodies through their mother’s milk. This natural protection can last 8-14 weeks.

* Puppies and kittens should NOT be vaccinated at less than 8 weeks. Maternal immunity will neutralise the

vaccine and little protection will be produced.

* Vaccination at six weeks will however, DELAY the timing of the first effective vaccine.

*Vaccinations given two weeks apart SUPPRESS rather than stimulate the immune system.

This would give possible new guidelines as follows:

1. A series of vaccinations is given starting at eight weeks of age (or preferably later) and given three-four weeks apart, up to 16 weeks of age.

2. One further booster is given sometime after six months of age and will then provide lifelong immunity.

In light of data now available showing the needless use and potential harm of annual vaccination, we call on our profession to cease the policy of annual vaccination.

Can we wonder that clients are losing faith in vaccination and researching the issues for themselves? We think they are right to do so. Politics, tradition, or the economic well being of veterinary surgeons and pharmaceutical companies should not be a factor in making medical decisions. It is accepted that the annual examination of a pet is advisable. We undervalue ourselves however, if we hang this essential service on the back of vaccination and will ultimately suffer the consequences. Do we need to wait until we see actions against vets, such as those launched in the state of Texas by Dr Robert Rogers DVM? He asserts that the present practice of marketing vaccinations for companion animals constitutes fraud by misrepresentation, fraud by silence and theft by deception.

The oath we take as newly qualified veterinary surgeons is "to help, or at least do no harm". We wish to maintain our position within society, and be deserving of the trust placed in us as a profession. It is therefore our contention that those who continue to give annual vaccinations in the light of the new evidence may well be acting contrary to the welfare of the animals committed to their care.

Yours faithfully

Richard Allport BVetMed MRCVS
Sue Armstrong MA VetMB MRCVS
Mark Carpenter BvetMed MRCVS
Sarah Fox-Chapman MS DVM MRCVS
Nichola Cornish BvetMed MRCVS
Tim Couzens BvetMed MRCVS
Chris Day MA VetMB MRCVS
Claire Davies BVSc MRCVS
Mark Elliott BVSc MRCVS
Peter Gregory BVSc MRCVS
Lise Hansen DVM MRCVS
John Hoare BVSc MRCVS
Graham Hines BVSc MRCVS
Megan Kearney BVSc MRCVS
Michelle L’Oste Brown BVetMed MRCVS
Suzi McIntyre BVSc MRCVS
Siobhan Menzies BVM&S MRCVS
Nazrene Moosa BVSc MRCVS
Mike Nolan BVSc MRCVS
Ilse Pedlar MA VetMB BSc MRCVS
John Saxton BvetMed MRCVS
Cheryl Sears MVB MRCVS
Jane Seymour BVSc MRCVS
Christine Shields BVSc MRCVS
Suzannah Stacey BVSc MRCVS
Phillip Stimpson MA VetMB MRCVS
Nick Thompson BSc BVM&S MRCVS
Lyn Thompson BVSc MRCVS
Wendy Vere VetMB MA MRCVS
Anuska Viljoen BVSc MRCVS
Wendy Vink BVSc MRCVS