As the subject of annual boosters crops up quite often, some might be interested in this letter printed in the Veterinary Times recently, signed by a number of UK vets. It gives food for thought if nothing else!
Dear Editor
We, the undersigned, would like to bring to your attention our concerns in
the light of recent new evidence regarding vaccination protocol.
The American Veterinary Medical Association Committee report 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, 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 that: '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 (39 March/April 2003) is also interesting reading:
'Current knowledgte 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, lifelong.'
Further, the evidence shows that the duration of immunity for rabies
vaccine, canine distemper vaccine, canine parvovirus vaccine, feline
panleukopaenia vaccine, feline rhinotracheitis and feline calicivurus have
all been demonstrated to be a minimum of seven years, by serology for rabies
and challenge studies for all others.
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
annual vaccines. We, however, fully support the recommendations and
guidelines of the American Animal Hospitals Association Taskforce, 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.
* 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.
* 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 mothers' milk.
This natural protection can last eight to 14 weeks.
* Puppies and kittens should NOT be vaccinated at less than eight 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.
* Vaccines 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 to 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 life-long 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 issue 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? 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 new evidence may well be acting contrary to the wefare of the animals
committed to their care.
Yours faithfully
Richard Allport, BVetMed, MRCVS
Sue Armstrong, MA BVetMed, 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 Pedler, 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, and
Wendy Vink, BVSc, MRCVS.
