| What Everyone Needs to Know About Canine Vaccines
and Vaccination Programs
Ron Schultz, PhD; University of
Wisconsin - Madison
For many veterinary
practitioners canine vaccination programs have been "practice management tools"
rather than medical procedures. Thus, it is not surprising that attempts to
change the vaccines and vaccination programs based on scientific information
have created great controversy and unique methods of resistance to the proposed
changes have been and are being developed. For some practitioners the issues are
not duration of immunity for the vaccines, nor which vaccines are needed for the
pet, instead it is felt that every licensed vaccine should be given to every pet
on an annual or more often basis. Ironically this is fostered by the fact that
multivalent products with 7 or more vaccine components can be purchased for the
same price or less than a product with one or two vaccine components. A "more is
better" philosophy prevails with regard to pet vaccines. On many occasions
practitioners say that "I know many of the vaccines I administer probably aren't
needed but it won't hurt to give them and who knows the animal may need them
some time during their life because of unknown risk." I have also been told by
many practitioners that "I believe the duration of immunity for some vaccines
like distemper, parvovirus and hepatitis is many years, but until I find another
way to get the client into my office on a regular basis I'm going to keep
recommending vaccines annually." Annual vaccination has been and remains the
single most important reason why most pet owners bring their pets for an annual
or more often "wellness visit." The importance of these visits for the health of
the pet is exceptional. Therefore, dog owners must understand the vaccines are
not the reason why their dog needs an annual wellness visit. Another reason for
the reluctance to change current vaccination programs is many practitioners
really don't understand the principles of vaccinal immunity. A significant
number of practitioners believe:
1) the annual revaccination
recommendation on the vaccine label is evidence the product provides immunity
for (only) one year. - Not True
2) that they are legally required
to vaccinate annually and if they don't they will not be covered by A VMA
liability insurance if the animal develops a vaccine preventable disease - Not True. Furthermore, certain companies will
not provide assistance if practitioners don't vaccinate
annually with
core vaccines. Not True - In fact most of
the companies have now demonstrated
their core products provide at
least 3 years of immunity .
3) that not revaccinating will
cause the animal to become susceptible soon (days or a few weeks) after the one
vear. - Not True
4) if the animal is not
revaccinated at or before one year the "whole vaccination program needs to be
started again". - Not True
5) if they don't continue to
revaccinate annually, diseases like canine distemper, canine parvovirus and
infectious canine hepatitis (CA V-I) will "reappear and cause widespread disease
similar to what was seen prior to the development of vaccines for these
diseases." - Not True
6) that if the revaccination
"doesn't help, it won't hurt." - Not True
7) that giving a vaccine
annually that has a duration of immunity of 3 or more years provides much better
immunity than if the product is given only once during the three years. - Not
True In fact, there are regional/state rabies programs that suggest annual
rabies vaccination programs provide better protection than revaccination once
every three years regardless of whether a 1 year or 3 year rabies product is
used. - Not True
8) that parvovirus vaccines only
provide six months of immunity, thus they must give them semi- annually and the
CPV -2 vaccines need to be given with coronavirus vaccine to prevent enteritis.
- Not True
9) "It's much cheaper to
revaccinate the pet annually than it is to treat the disease the animal will
develop because it didn't get revaccinated annually." The "better safe than
sorry" philosophy - It is less expensive to
prevent disease. However, if the core vaccines are given as a puppy and again at
a year of age, then annual vaccination is not needed. Furthermore, if a vaccine
is given that is not needed and it causes an adverse reaction that is
unacceptable and very expensive.
10) they need to revaccinate all
new dogs/cats coming to their clinic irrespective of vaccination history even
when vaccination records are available from another clinic. Presumably the
"other clinic" used the wrong vaccine or didn't know how to vaccinate. - Not
True
11) "Dogs need to be
revaccinated annually up to 5 to 7 years of age, then and only then would
vaccination every three years be okay.." - Not True
12) "Surgical procedures,
including anesthesia, are immunosuppressive thus dogs should be vaccinated prior
to or shortly after surgery." - Not True
13) "Because boarding kennels
require annual or more often (kennel cough every 3 to 6 months) vaccination,
practitioners must continue vaccinating annually with all vaccines." - Not True-
help change the kennel rules through education and just use the vaccines that
need to be given (eg Kennel Cough.)
Note: There are kennels that
require every licensed vaccine and the vaccines must have been given within 1
year or less prior to admission - help
change these rules! Those kennels that are members of the American Kennel
Association should be following the AAHA Guidelines, but many kennels do not
belong to this association.
It will be necessary to correct
many of these and additional misunderstandings by providing education to
veterinary practitioners, kennel owners and pet owners before significant
changes in vaccination programs can or will occur to reduce the over-vaccination
of both cats and dogs. However it is equally important that we don't, in our
efforts to prevent over-vaccination, fail to vaccinate often enough, fail to
vaccinate all or as many pups with the core vaccines, fail to use products that
are necessary, or to use products that don't provide protection in our pets.
I believe every practitioner,
kennel owner and dog owner should know the following general information about
canine vaccines and vaccination programs. What vaccines are needed for all
puppies? I do mean all pups, as we only vaccinate 50% of
dogs. If we could increase this percentage to 75%, we would be able to eliminate
many of the diseases prevented by core vaccines. The "core vaccines," those that
every pup should receive and identified as core by most canine vaccine experts
in the United States, include: 1) Canine Parvovirus type 2 (CPV -2), 2) Canine
Distemper virus (CDV), 3) Canine Adenovirus type 2 (CA V-2), 4) Rabies Virus
(RV). When do the core vaccines need to be given? As a minimum, puppies
should be given at least one dose at 16 weeks of age or older. Preferably, they
should be given three or more times starting at 6 to 9 weeks then at an interval
of 2 to 4 weeks revaccinate 9 to 12 weeks then again at 14 to 16 weeks. It is
critical that the last dose be given at 14 to 16 or more weeks of age. It is
important not to give them earlier than 6 weeks unless there is a significant
risk of a specific disease, then give only the vaccine for the disease you want
to prevent (e.g. CPV -2). Never vaccinate a pup less than 4 weeks of age. The
most effective canine core products currently include modified live and
recombinant vaccines alone or in combination. The combination products with
CPV-2, CDV and CAV -2 currently often include canine parainfluenza (CPI) virus.
New "core only" products have been and are being developed that don't have CPI,
however, the CPI will not cause a problem if and when used as a parenteral 5 way
combination product.
After the puppy series is
completed, revaccination is recommended again at one year of age or one year
after the last puppy vaccination. Rabies must be given again at 1 year, then
every 3 years, whereas, the other core vaccines need not be given again for at
least 3 or more years. There is no benefit from annual rabies vaccination and
most one year rabies products are similar or identical to the 3-year products
with regard to duration of immunity and effectiveness. However, if they are 1
year rabies vaccines, they must be legally given annually! Rabies vaccine is the
only canine vaccine requiring a minimum duration of immunity study. However,
revaccination annually does not necessarily improve immunity. However, annual
vaccination does significantly increase the risk for an adverse reaction in the
dog. I would recommend, if you really want to be sure the puppy vaccination
program was successful, that a CDV and CPV- 2 antibody titer be performed 2 or
more weeks after the last puppy vaccination. Laboratory tests as well as
"in-office test" for CDV and CPV-2 tests are available. If there is no antibody,
revaccinate and perform a test two or more weeks after revaccination. If you
still don't have antibody, change the product and vaccinate again. Antibody
tests (titers) are very useful at these times to ensure the animal is immunized.
The problem with antibody tests is they are very expensive, thus in general,
these tests won't be used. As an alternative to revaccinating at one year for CD
V, CPV -2 and CA V -2, I would revaccinate at 6 months to ensure the animal has
responded rather than waiting until 1 year. Then, revaccinate not more often
than every 3 years. The minimum duration of immunity for the core vaccines
except rabies is at least 7 years based on challenge and/or titers (Table 1).
Thus revaccinating annually will not improve protection. Ironically "the better
safe than sorry philosophy" can be equally applied to less vaccination, since
the animal that develops an adverse reaction (e.g. hives, facial edema,
anaphylaxis) from a vaccine that wasn't needed is an example of "being sorry,
not safe!"
What about all the other
vaccines currently available for the dog? They are non-core or optional
vaccines that should only be given to animals that need them and only as often
as needed. There are also some vaccines that are not recommended for any
dogs. The duration of immunity is not known for certain non-core products, the
efficacy is limited or not known and the risk vs. benefit factors are not always
well established nor understood. The minimum duration of immunity for
Leptospira vaccines is probably less than one year, thus if required for
a high risk dog, they may need to be given as often as semi-annually.
Considering the low efficacy, the adverse event rate and the minimal risk for
leptospirosis in many regions of the US, certain practitioners are not using the
current products. However if an animal is in a high-risk environment for
leptospirosis, the product to use should contain the 4 serovars (there is no
significant cross protection among the 4 current serovars) and the animal should
be vaccinated starting not earlier than 12 weeks of age, revaccinate in 2 to 4
weeks, revaccinate at 6 months of age, revaccinate at a year of age and then you
may have to revaccinate as often as every 6 to 9 months for optimal protection.
Using this program the animal should not develop clinical disease but it can get
infected and shed organisms in its urine. Bordetella immunity may be less than
one year and the efficacy for the products is not well established. Many animals
receive "kennel cough" vaccines that include Bordetella and CPI and/or CAV-2
every 6 to 9 months without evidence that this frequency of vaccination is
necessary or beneficial. In contrast, other dogs are never vaccinated for kennel
cough and disease is not seen. CPI immunity lasts at least 3 years when given
intranasally, and CAV -2 immunity lasts a minimum of 7 years parenterally for
CAV-I. These two viruses in combination with Bordetella bronchiseptica
are the agents most often associated with kennel cough, however, other
factors play an important role in disease (e.g. stress, dust, humidity, molds,
mycoplasma, etc.), thus kennel cough is not a vaccine preventable disease
because of the complex factors associated with this disease. Furthermore, this
is often a mild to moderate self limiting disease. I refer to it as the "Canine
Cold." My preference when a kennel cough vaccine is used is that it should be
the intranasal rather than the parenteral, but some dogs will not allow someone
to administer the vaccine intranasally.
There is a new virus of dogs, an
"equine-like influenza virus," that first infected greyhounds in Florida in 2004
that caused respiratory disease. At this time it is not known whether this
virus, referred to as canine influenza virus (CIV), is an important cause of
canine respiratory disease, nor if it will be an emerging disease of dogs.
Questions about the role of influenza virus or for that matter, viruses other
than CPI and CAV - 2, bacteria other than
Bordetella bronchiseptica, various mycoplasmas and other factors causing
kennel cough, which I refer to as "Canine Respiratory Disease Complex," exist
and must be answered.
The geographic distribution of
Lyme disease would suggest vaccination would only be of benefit in certain
regions of the US, thus widespread use of this product is neither necessary nor
desired. Although Wisconsin is an endemic area for Lyme disease, we have used
very few doses of Lyme vaccines in our VMTH and we have not seen significant
numbers of cases of Lyme disease. However in certain areas of western and
northwestern Wisconsin and eastern Minnesota, many cases of confirmed Lyme
disease are seen in both vaccinated and unvaccinated dogs. Tick control for
prevention and antibiotics for treatment must be used in high risk areas.
Immunity to Lyme vaccines have been shown experimentally to last up to one year.
Giardia is a new vaccine that may be of value in certain circumstances, but
there have not been adequate field studies to demonstrate the need nor the
benefit of this vaccine. To date no one has demonstrated a benefit for
coronavirus vaccine. In the vaccination guidelines from the American Animal
Hospital Association, neither Giardia nor Coronavirus vaccines are recommended
unless they can be proven to be beneficial for a specific animal. There are also
new vaccines for snakebites (Crotalus sp.) and for periodontal disease
(Porphyrius sp.) and a therapeutic vaccine for treatment of canine
melanomas.
At present most canine core
vaccines are given more often than needed, but a few non-core vaccines probably
not often enough to be of benefit. Also, many vaccines are given that are not
needed or that cannot be shown to provide a benefit for the specific animal.
Vaccines are medical products that should only be given if needed and only as
often as is necessary to provide protection from diseases that are a risk to the
health of the animal. If a vaccine that is not necessary causes an adverse
reaction that would be considered an unacceptable medical procedure, thus use
only those vaccines that are needed and use them only as often as needed.
Vaccination programs are
changing and they will continue to change. The vaccination program must be
tailored to the individual animal. Vaccines are medical products that should not
be used as practice management tools. My general philosophy is to vaccinate more
animals in the population, but vaccinate with only those vaccines that the
animal needs and only as often as required to maintain protective immunity. For
some products vaccination may occur once or twice in a life time, whereas for
other products it may be every 6 to 9 months.
Be wise and
immunize, but immunize wisely!
|
Table 1: Minimum Duration of Immunity for Canine
Vaccines |
|
Vaccine |
Minimum Duration
of Immunity |
Methods Used to
Determine Immunity |
|
CORE VACCINES |
|
Canine Distemper Virus
(CDV) |
|
|
|
Rock born Strain |
7 yrs/15 yrs |
challenge/serology
|
|
Onderstepoort Strain |
5 yrs/9
yrs |
challenge/serology |
|
Canarypox Vectored rCDV |
3 yrs/4 yrs
|
challenge/serology |
|
Canine Adenovirus-2 (CAV
-2) |
7 yrs/9
yrs |
challenge-CAV-l/serology |
|
Canine
Parvovirus-2 (CPV -2) |
7 yrs/10 yrs |
challenge/serology |
|
Canine Rabies |
3 yrs/5
yrs |
challenge/serology |
Why Vaccination Programs are
Changing
Why, when you know from personal
experience that life-long immunity exists for many human vaccines, do you have
great difficulty believing a canine vaccine can provide life-long immunity?
Perhaps I and my colleagues that teach immunology to veterinary medical students
have failed to explain the basics of vaccine induced "immunologic memory."
Immunologic memory is as the term implies the immune system's ability to
remember the vaccine antigens that it has seen at an earlier time in life,
allowing the immune system to respond in a manner that will protect you or your
dog from specific infections and/or diseases.(1,2)
Immunologic memory is
responsible for the duration of immunity that develops after recovery from
natural infection/disease and after vaccination with modified live virus (ML V)
or killed virus (KV) vaccines. Similarly bacterial infections and vaccines or
bacterins (killed bacterial vaccines) provide immunologic memory. However, in
general, immunologic memory to killed viral vaccines and to bacterial vaccines
(or bacterins) is not as long lived as it is to ML V vaccines. The duration of
immunity or length of immunologic memory varies among the agents causing the
diseases. For example, our immunologic memory for measles virus is life-long.
How do we know that it is lifelong? No one has published any controlled studies,
but we know after recovering from measles infection and/or vaccination with a ML
V vaccine, immunity is life-long because people rarely get measles even though
they rarely receive another dose of vaccine. In contrast to the ML V vaccine,
the killed measles vaccines that were used for a short period of time about 25
years ago failed to give life-long immunity. Many individuals receiving killed
vaccines were either inadvertently infected or had to be revaccinated with a ML
V when they were 15 to 20 years of age to provide life long immunity. How many
people do you know that were vaccinated with the modified live measles virus
product, in use for approximately 40 years, or that had measles as a child, then
developed measles later in their life? I'm sure your answer must be very few or
none!
A very similar story to measles
can be told for canine distemper virus (CDV) in the dog. CDV is in the same
virus family as measles virus and it shares many similarities with MV. As you
may know, MV vaccines have been and were available until recently for dogs to
prevent disease (not infection) caused by CDV. Those of you over the age of 50,
may remember canine distemper when it was a devastating disease killing many
animals with more than 50% of infected puppies often dying from the disease. If
you are old enough, were observant enough and had an opportunity to follow dogs
that recovered from natural infection with CDV you know that dogs recovering
from CDV, like their human counterpart recovering from measles, rarely, if ever,
developed acute distemper during the rest of life, even when not revaccinated.
Like measles immunity in humans, immunity from canine distemper infection
confers immunologic memory resulting in life- long immunity. How do I and my
older, wiser and now retired colleagues and canine infectious disease experts,
Dr. Max Appel, Dr. L.E. (Skip) Carmichael, and Dr. Larry Swango know that
distemper immunity is life long? We know because we had the opportunity to
follow dogs that recovered from infection with CDV or puppies that were
vaccinated once or twice with MLV CDV and lived for 7 or more years and never
developed disease even though they were exposed to CDV via natural outbreaks or
experimental challenge with CDV. We also know the vaccinated or recovered dogs
had life long immunity because we and others performed antibody titer tests for
years on the dogs after they recovered from infection or after puppy
vaccination. These dogs all had titers showing that immunologic memory was
present. Most of the dogs had titers that provide sterile immunity (protection
from infection) much like the measles titers found years later in many
vaccinated or naturally infected people. However even if the dogs didn't have
sterile immunity but still had antibody, they had immunologic memory. An
antibody titer no matter how low shows the animal has immun9logic memory since
memory effector B cells must be present to produce that antibody. Some dogs
without antibody are protected from disease because they have T cell memory,
that will provide cell mediated immunity (CMI). CMI will not protect from
reinfection, but it will prevent disease. When an animal is antibody negative it
may have T cell immunologic memory, but I generally consider a CDV antibody
negative dog not to be protected, therefore, I recommend revaccination!. Some
researchers, including myself, have had the opportunity to follow the duration
of immunity for dogs living in natural or experimental environments that are
free of CDV and CPV-2 (6). Why is it important that observations are made on
dogs and cats that are not exposed to the virus? Because in those environments
it is possible to demonstrate that immunologic memory is independent of natural
or overt stimulation with the wild type virus or the vaccine virus. However, in
a normal environment where infection occurs, "natural vaccination" or exposure
and infection with the specific
agent can and does occur at least for certain agents and in certain animals, but
the infected animals do not get sick. Ironically when animals have "sterile
immunity" their immune system is rarely boosted by natural exposure since
infection does not occur. If infection does not occur, there is no stimulation
of the specific memory T or B cells, thus the antibody titer does not increase.
A severe outbreak ofCPV-2 occurred in a large commercial breeding kennel, where
more than 90% of puppies got sick and 50% of puppies from 4 weeks to 24 weeks of
age died. However, none of more than 50 dams with sick and dying puppies had a
significant increase in antibody titer, none had virus in their feces and none
showed clinical signs of CPV -2 disease, all excellent indicators the dams had
sterile immunity (did not get infected)!
Is immunologic memory and
duration of immunity to all human viruses life-long? The answer is NO! Natural
infection with many human viruses and the vaccines for those viruses provide
life- long immunity (e.g. measles, mumps, rubella), whereas other viruses and/or
the vaccines for them provide short duration of immunity (e.g. human cold
viruses, influenza virus) and for additional viruses there is no immunity from
infection or experimental vaccines (e.g. HIV).
The three most important viral
infections of dogs all provide life-long immunity, they are CDV, CPV-2, and
CAV-I. If a puppy is immunized with the three MLV vaccines used to prevent these
diseases, there is every reason to believe the vaccinated animal will have up to
life-long immunity! The vaccines that prevent the diseases caused by these 3
viruses plus rabies vaccine are the "Canine Core Vaccines" or those vaccines
that every puppy should receive. My own dogs, those of my children and
grandchildren are vaccinated with ML V CDV, CPV-2, CPI, and CAV-2 vaccines once
as puppies after the age of 12 weeks. An antibody titer is performed two or more
weeks later and if found positive our dogs are never again vaccinated. I have
used this vaccination program with modifications (CAV-2 replaced CAV-I vaccines
in 1970's and CPV-2 vaccines were first used in 1980) since 1974! I have never
had one of our dogs develop CDV, CAV-1 or CPV-2 even though they have had
exposure to many dogs, wildlife and to virulent CPV-2 virus. You may say that I
have been lucky, but it is not luck that protects my dogs, it is immunologic
memory.
An important factor contributing
to life long immunity in addition to the memory T and B cells and the "memory
effector B cells" (long lived plasma cells) of the specific (adaptive) immune
system is the innate immune resistance associated with age. It is well known in
all species that the young animal is more susceptible to infection and disease
than a mature animal. In the case of human infections that period of increased
susceptibility is often 'the first few years of life, and especially the first
year. In the puppy and the kitten it is often the first 3 to 6 months of life,
but it can be up to 1 year of age that the animal is more susceptible to
disease. For example, dogs less than a year of age are much more likely to
develop severe parvoviral disease than susceptible (immunologically naive) dogs
over one year of age even though at both ages the animals are very susceptible
to infection with CPV -2. Similarly a susceptible cat less than one year of age
and especially cats less than 3 months of age are at much greater risk of
becoming persistently infected with feline leukemia virus than a susceptible cat
that is greater than one year of age at the time of infection. Thus innate as
well as specific immune factors contribute to age- related resistance and these
factors are highly complex and not completely understood. However, age related
resistance plays a critical role in life-long or long term immunity. This does
not imply that older dogs and cats cannot get infected and develop disease, it
is that they are much less likely to get disease when compared to the younger
animal.
I and my colleague, Dr. Fred
Scott, first proposed a three year revaccination program for dogs and cats more
than 25 years ago, when we published an article in Veterinary Clinics of North
America 8(4) 755-768, 1978. Today, a three year revaccination program has been
recommended in the AAHA Canine Vaccination Guidelines and the American
Association of Feline Practitioners Vaccine Guidelines for Cats. The proposed
change for revaccination with "Core Vaccines" from annual to triennial
revaccination has been very controversial for many reasons, however, the reasons
have little or nothing to do with "immunologic memory" or duration of immunity.
No one has nor can anyone in the future, show that there is any immunologic
benefit from annual revaccination with MLV CDV, CAV or CPV-2. In fact, it may
even be difficult to show an immunologic benefit for revaccination at three year
intervals since most animals have long term immunity for CDV, CAV-1 and CPV-2.
Some among you are probably convinced that there is life long immunity to
certain vaccines used in dogs and cats, but few of you after many years of
performing annual revaccination are willing to take the risk, however small it
may be, to adopt the puppy vaccination program. However, you should feel
confident that adopting, a three year revaccination program for CDV, CAV and
CPV-2, will not increase the risk for diseases caused by these 3 viruses, just
as a once every three year revaccination, rather than annual revaccination, with
the killed rabies vaccines does not increase the animal's risk for rabies.
You and your veterinarian will
need to determine what vaccines and vaccination program is best for your pet and
their patient respectively. The program selected may only include core vaccines
that are given once in the lifetime of the dog or the program may include all
vaccines with revaccination on an annual or more often basis, or it may be a
vaccination program in between these two extremes depending on what your pet's
needs are and what, in the medical judgment of your veterinarian, is best for
their patients. Furthermore, it is likely your decision depend on the life style
of your pet, its medical history, health status, age, pregnancy status and other
important factors.
FREQUENTLY ASKED QUESTIONS (FAQ)
1. Is there a risk of
over-vaccinating a pet (e.g. injecting it too often, or using vaccines that are
not required for the specific pet)?
Yes - Vaccines should not be given needlessly, as they
may cause adverse reactions. Vaccines are medical
products that should be tailored to the needs of the individual animal.
2. May I mix different types
of vaccines in the syringe?
No - One should never mix different vaccine
preparations in the syringe unless specified by the data sheet.
3. May I co-inject different
vaccines (not part of a single commercial product) into the same animal?
Yes - but different vaccines
should be injected into separate sites that are drained by different lymph
nodes.
4. May I use smaller vaccine
doses in small breeds to reduce the risk of adverse reactions?
No - The volume (e.g. 1.0 ml) as recommended by the
manufacturer generally represents the minimum immunizing dose, therefore the
total amount must be given.
5. Should the large dog (Great
Dane) be injected with the same volume of vaccine as the small dog (Chihuahua)?
Yes - Unlike pharmaceuticals that are dose-dependent,
vaccines are not based on volume per body mass (size), but rather on the minimum
immunizing dose.
6. May I vaccinate the
anaesthetized patient?
It is best not to do this if
possible - the patient may develop a
hypersensitivity reaction and vomit, leading to an increased risk of aspiration.
Also, anaesthetic agents may be immunomodulatory .
7. May I vaccinate pregnant pets?
No - Vaccination with ML V and killed products
during pregnancy should be avoided, if at all possible.
8. May I vaccinate pets that
are on immunosuppressive or cytotoxic therapy (e.g. for cancer or
immune-mediated diseases, such as those with an autoimmune or hypersensitivity
pathogenesis)?
No - Vaccination especially with ML V products should
be avoided as they may cause disease; vaccination with killed products may not
be effective or may aggravate the immune-mediated disease.
9. How long after stopping immunosuppressive therapy do
I wait before vaccinating a pet?
A minimum of 2
weeks.
10. May I vaccinate every week
if an animal is at high risk of disease?
No - Vaccines should not be given more often than
every other week, even when different vaccines are being given.
11. When should the last
vaccine dose be given in the puppy and kitten vaccine series?
The last dose of vaccine should
be given at around 16 weeks of age.
12. May I inject a killed
vaccine, followed at a later time with a ML V for the same disease?
No - The killed vaccine may induce an effective
antibody response that will neutralize the ML V in the vaccine, thereby
preventing immunization. It would be preferable to give the ML V vaccine first
and if/when needed, revaccinate with the killed vaccine preparation.
13. May I inject a modified
live intranasal Bordetella vaccine?
No - The vaccine can cause a severe local reaction
and may even kill the pet.
14. May I give a killed
Bordetella vaccine destined for parenteral use intranasally?
No - This will not stimulate a specific response to
the Bordetella; you should give a live vaccine via the intranasal route,
as specified by the data sheet.
15. Are precautions necessary
when using MLV FHV-I/FCV parenteral vaccines in cats?
Yes - Mucosal (e.g. conjunctival and nasal) contact
with the preparation must be avoided, because the vaccine virus can cause
disease.
16. Can nosodes (holistic
preparations) be used to immunize pets?
No - Nosodes cannot be used for the prevention of any
disease. They do not immunize because they do not contain antigen.
17. Should dogs and cats with
a history of adverse reaction or immune-mediated diseases (hives, facial oedema,
anaphylaxis, injection site sarcoma, autoimmune disease, etc.) be vaccinated?
If the vaccine suggested to cause
the adverse reaction is a core vaccine, a serological test can be perfonned, and
if the animal is found seropositive (antibody to CDV, CPV-2, FPV) revaccination
is not necessary. If the vaccine is an optional non-core vaccine (e.g.
Leptospira bacterin) revaccination is discouraged. For rabies, the local
authorities must be consulted to detennine whether the rabies vaccine is to be
administered by law or whether antibody titre may be detennined as an
alternative.
18. May I use different
vaccine brands (manufacturers) during the vaccination program?
Yes - It may even be desirable to
use vaccines from different manufacturers during the life of an animal, because
different products may contain different serotypes (e.g. of feline calicivirus).
19. Should I use a
disinfectant (e.g. alcohol) on the injection site?
No - The disinfectant might inactivate an
ML V product, and it is not known to provide a benefit.
20. Can vaccines cause
autoimmune diseases?
Vaccines themselves do not cause
autoimmune disease, but in genetically predisposed animals they may trigger
autoimmune responses followed by disease - as can any infection, drug, or a
variety of other factors.
21. May I split vaccines in
combination products?
Yes - For
example, Leptospira bacterins are often the diluent for the viral antigen
combination. The "viral cake" may be resuspended in sterile water, and the
Leptospira bacterin be given separately at another site or time, or
discarded.
22. Will a single vaccine
dose provide any benefit to the dog or cat? Will it benefit the canine and
feline populations?
Yes - One
dose ofa MLV canine core vaccine (CDV, CPV-2 CAV-2) or a feline core vaccine
(FPV, FCV, FHV-1) should provide long term immunity when given to animals at or
after 16 weeks of age. Every puppy and kitten 16 weeks of age or older must
receive at least one dose of the MLV core vaccines.
If that were done, herd
(population) immunity would be significantly improved. Even in the USA with its
good vaccination record, probably <50% of all puppies and <25% of all
kittens ever receive a vaccine. We must vaccinate more animals in the population
with core vaccines to achieve herd immunity (e.g. 75% or higher) and prevent
epidemic outbreaks.
23. When an animal first
receives a vaccine that requires two doses to immunize (e.g. killed vaccines
like Leptospira bacterins or feline leukemia virus), and it does not
return for the second dose within ~6 weeks, is there any immunity?
No - A single dose ofa two-dose vaccine does not
provide immunity. The first dose is for priming the immune system, the second
for boosting. If a second dose is not given within 6 weeks of the first, the
regime must start again, making sure the two doses are given within 2 to 6
weeks. After those two doses, revaccination with a single dose can be done at
any time.
24. May I give a MLV product
to a wild, exotic species or to a domestic species other than to the ones which
the vaccine was licensed to protect?
No - Never. Many MLV vaccines
have caused disease in animal species other than those for which they had been
licensed. Even worse: the vaccine could be shed from those animals, regain
virulence through multiple passages and cause disease even in the target species
for which it had been developed. The consequences could be catastrophic!
A highly effective and very safe
vaccine for species that are susceptible to CDV is a canary poxvirus-vectored
recombinant CDV vaccine that is available as a monovalent product for ferrets or
a combination product for dogs. The monovalent vaccine is being used in many
wild and exotic species susceptible to CDV.
25. May I vaccinate a puppy
that is at high risk of getting CDV with a human measles vaccine?
No - Due to an insufficient
amount of virus, the human MV vaccine is not immunogenic in the puppy. Measles
virus vaccines made specifically for the dog (sometimes combined with CDV) will
give temporary protection at an earlier age than a CDV vaccine. At 16 weeks or
older, the puppy must be vaccinated with a CDV vaccine, to achieve permanent
immunity.
26. I know that maternally
derived antibodies (MDA) can prevent active immunization with MLV vaccines
- but can they also block immunity
to killed vaccines?
Yes - MDA can indeed block certain killed vaccines.
If the killed product requires two doses, as is often the case, and the first
dose is blocked by MDA, then the second dose will not immunize. In this
circumstance, the second dose will prime (if not blocked), and a third dose is
required to boost and immunize.
This is not true for MLV,
where - in the absence of MDA - it
only takes a single dose to prime, immunize, and boost. Nevertheless two doses
are often recommended, particularly in young animals, to be sure one is given
when MDA cannot block. That is why in the puppy or kitten series, the
last dose should be given at around 16 weeks of age or later.
27. I have been told that
certain canine MLV combination core products need only be given twice, with the
last dose at an age as young as 10 weeks. Is that accurate?
No - it is not. No combination
core product currently available will immunize an acceptable percentage of
puppies when the last dose is given at 10 weeks of age. The last dose should be
given at around 16 weeks of age, regardless of the number of doses given
earlier.
In the presence of MDA, MLV
vaccines either immunize or they don't, and the animal will be either immune or
not immune - there is nothing in between.
MLV vaccines do not give a little immunity with any dose when blocked by MDA.
28. For how long can a
reconstituted MLV vaccine sit at room temperature without losing activity?
At room temperature, some of the
more sensitive vaccines (e.g. CDV, FHV-1) will lose their ability to immunize in
2 to 3 hours, whereas other components will remain immunogenic for several days
(e.g. CPV, FPV).
29. May I give the same type
of vaccine parenterally and intranasally, for example the canine and feline
vaccines used to prevent respiratory diseases ('kennel cough' and feline upper
respiratory disease)?
Yes - But be
sure to give the product approved for that route. If you use the parenteral MLV
vaccines containing FCV and FHV-1 locally, you could cause disease in the cat.
If you use the killed FCV and FHV-1 vaccines locally, you would not get any
immunity and might cause significant adverse reactions. If you gave the
intranasal live 'kennel cough' vaccine parenterally, you could cause a severe
necrotizing local reaction and even kill the dog, whereas giving the parenteral
killed Bordetella vaccine intranasally will not immunize and may cause a
hypersensitivity reaction.
However, both types of products
can be given at the same time or at various times in the life of the animal.
Vaccinating both parenterally and intranasally may actually provide better
immunity than vaccinating at only one site. Thus parenteral vaccination provides
protection in the lung but little or no immunity in the upper respiratory tract
(especially local secretory IgA and CMI), whereas intranasal vaccination will
engender good secretory IgA and local CMI and non-specific immunity (e.g. type I
interferons), but will not always provide immunity in the lung.
30. Are there dogs and cats
that cannot develop an immune response to vaccines?
Yes - This
is a genetic characteristic seen particularly in some breeds, and these animals
are called 'non-responders'. Genetically related (same family or same breed)
animals will often share this non-responsiveness. If the animal is a
non-responder to a highly pathogenic agent, like canine parvovirus or feline
panleukopenia virus, the infected animal will die if infected. If it is a
non-responder to a pathogen that rarely causes death, it may become very sick
but will survive (e.g. after a Bordetella bronchiseptica infection).
31. Are there mutants
(biotypes or genotypes) of CDV or CPV-2 in the field that the current vaccines
cannot provide protective immunity against?
No. - All the current CDV and
CPV-2 vaccines provide protection from all the known isolates of CDV or CPV-2,
respectively, when tested experimentally as well as in the field.
32. How long after
vaccination does it take for the dog to develop immunity that will prevent
severe disease when the core vaccines are used?
This is dependent on the animal,
the vaccine, and the disease.
- The
fastest immunity is provided by CDV vaccines - MLV and recombinant canarypox
virus vectored. The immune response starts within minutes to hours and
provides protection within a day to animals without interfering levels of MDA
and dogs that are not severely immunosuppressed.
- Immunity
to CPV-2 and FPV develops after as few as 3 days and is usually present by 5
days when an effective ML V yaccine is used. In contrast, the killed CPV-2 and
FPV-2 vaccines often take 2 to 3 weeks or longer to provide protective
immunity.
- CAV-2 MLV
given parenterally would provide immunity against CAV-1 in 5 to 7 days; when
given intranasally, however, the same level of immunity to CAV-1 is not
present until after 2 or more weeks.
- Time from
vaccination to immunity is difficult to determine for FCV and FHV-1 because
some animals will not develop any immunity.
33. Will the current 'kennel
cough' vaccines provide any protection from disease caused by the new canine
influenza virus?
No - The
racing greyhounds that have been found infected and that developed disease had
been routinely vaccinated 3 or more times a year with commercial 'kennel cough'
vaccines. Canine influenza virus is antigenically unrelated to any other virus
of dogs, but related to Equine Influenza Virus.
34. If an animal has gone
beyond the time that is generally considered to be the maximum DOl for the
vaccine (7 to 9 years for CDV, CPV-2, CAV-2; >1 year for Leptospira,
Bordetella bronchiseptica; >3 years for rabies), do I have to start the
series of vaccinations again (multiple doses 2 to 4 weeks apart)?
No - For
MLV vaccines, multiple doses are only required at the puppy or kitten age, when
an animal has MDA.
35. What can I expect from
the core vaccines in terms of efficacy in the properly vaccinated puppy/dog and
kitten/cat?
- Dogs properly vaccinated with
MLV or recombinant CDV, CPV-2 and CAV-2 would have ≥98% protection from
disease. Similarly we would expect a very high protection from infection.
- For the properly vaccinated
cat that had received ML V vaccines, we would estimate that ≥98% would be
protected from disease and infection with FPV.
- In
contrast, we can expect FCV and FHV-1 vaccines, at best, to protect from
disease, especially in a highly contaminated environment (e.g. shelter) and
protection would be seen in 60 to 70% in a high risk environment and higher in
the household pet cat.
36. Are serum antibody titres
useful in determining vaccine immunity?
Yes -
Especially for CDV, CPV-2 and CAV-1 in the dog, FPV in the cat and rabies
virus in the cat and dog. Serum antibody titres are of limited or no value for
the other vaccines. Assays for CMI are of little or-no value for any of the
vaccines for various technical and biological reasons. Such factors are less of
an issue for serological tests where it is much easier to control many of the
variables. However, discrepant results are still obtained, depending on the
quality assurance program of the given laboratory.
37. Do puppies develop
immunosuppression after the initial series of core vaccines?
Yes - If a combination product containing MLV-CDV and
MLV-CAV-2 with other components is used, a period of immunosuppression lasting
approximately 1 week develops, beginning 3 days after vaccination. If the
combination vaccine does not contain either MLV-CDV or MLV- CAV-2, then such
suppression does not occur.
Biographical Profile
Dr. Ron Schultz earned
his BS degree (1966), MS (1967) and PhD in Immunology and Veterinary Pathology
(1970) from the Pennsylvania State University. From 1970 to 1978 he was an
Assistant then Associate Professor at NY State College of Veterinary Medicine,
James A. Baker Institute, Cornell University. He established the first
Veterinary Clinical Immunology Laboratory in the US while on the faculty at
Cornell. He also served as Associate Director of the Human Health Service
Laboratory at Cornell University. From 1978 to 1982 he was a Professor and
Director of the Veterinary Clinical Immunology Laboratory that he established in
the School of Veterinary Medicine, Auburn University. He accepted his current
position as Professor and Chair of the Department of Pathobiological Sciences,
School of Veterinary Medicine, UW- Madison in 1982. At the time he accepted this
position he was the only member of the department which now has many faculty,
staff and students, including faculty in the Wisconsin Veterinary Diagnostic
Laboratory. He is an honorary diplomate of the American College of Veterinary
Microbiologists. Dr. Schultz has won several awards, is a member of numerous
professional organizations and served or serves on numerous Editorial Boards and
National and International advisory panels He is on the AAHA Canine Vaccine Task
Force, the AAFP Feline Vaccine Task Force that provide Guidelines for Canine and
Feline Vaccines and Vaccination Programs as well as the Vaccine Guideline Group
for the World Small Animal Veterinary Association. He has served on National
Academy of Science panel to review USDA Grants Programs and was recently invited
to be a Member of the Assessment Panel to review research programs of the USDA's
Agriculture Research Service Laboratories throughout the US. He was the first
president of the American Association of Veterinary Immunologists and has been
president of the Conference of Research Workers in Animal Disease. He has
published more than 200 papers on the immunology and microbiology of animal
disease, clinical immunology and vaccinology and has edited several books and
holds multiple patents. He has trained more than 50 graduate students and
postdoctoral fellows in his laboratories at Cornell, Auburn and Wisconsin. He
has received millions of dollars in extramural research funds for research
primarily to study diseases of dogs, cats and cattle and also received funding
for instructional training programs.
What Everyone Needs to Know About Canine Vaccines and
Vaccination Programs – conference notes
The three MOST important things you can give your puppy:
Training
Love
Vaccines
Types of Vaccines that are available
-Live attenuated (MLV) Vaccine –
majority of canine viral vaccines and they are most like natural
immunization. It was fully live, for example, distemper could
be given live and half of the puppies given the vaccine would survive and half
would die.
-Not all species react the same way
to vaccines. For example a ferret could get distemper from a
MLV vaccine. Only give MLV to the appropriate species as
indicated on the label.
-Individuals with severely
compromised immune systems should not receive MLV, like a human with HIV
Small pox was eradicated with a MLV
-Vector vaccine – genetically live
vaccine. This is basically a genetically altered virus
cells. The gene inserted into an attenuated virus or
bacteria. Live attenuated vaccine having protective antigenic
protein is produced. Basically delete or take genes from a
virus and alter them. Genetically engineered vaccines are on
the forefront. You can better control what is in the vaccine
(by controlling the virus or bacteria). Traditionally, if a
vaccine is safer, it is less effective. If it is more
effective it is less safe. Not with genetically engineered
vaccine.
-Killed Vaccine – take the virus
and chemically treat the virus/bacteria, add and agivent to make it more
effective and stable.
-Recombinant subunit
vaccine. Grow the organism, chemically inactivate it and then
extract the antigenic proteins and material. In this vaccine
all other materials can be removed and therefore these cause less reactions.
Innate vs acquired immunity
Innate
Present from birth
Operates against any substance
Not enhanced by prior exposure
Age – younger/older have different levels of innate immunity
Acquired/adaptive/specific
Defense mechanisms tailored to individual pathogens
Enhanced by prior exposure – great lifetime memory for diseases
*MMR in humans is very similar to Distemper/Parvo and Adeno
(hepatitis)
*Leptobactrins are only effective
for 6-9 months and they are limited to the strains included in the vaccine.
*the lymph nodes, particularly the
thymus affect the modulation of acquired immunity, the other lymph nodes in the
body affect the modulation of acquired immunity
Vaccines rarely enhance the innate immunity, but some do –
like the intranasal bordatella vaccine by activating the interferons in the
body. Vaccines are designed to enhance Acquired Immunity.
The bordatella vaccine will NOT prevent diseases, but it tests the immune
system.
The immune system is part of the
whole … must look at the whole system it is part of the lymph, endocrine,
reproductive, neurologic and hemotologic systems.
Infection does not equal disease. Many
dogs are often infected but few develop clinical disease.
Thus, infection is much more common than disease.
Example, many dogs can get
infected with borrielia burgdorferi, the cause of Lyme
disease, but very few dogs develop the disease.
Disease depends on the dose, the route of exposure and the
virulence of the pathogen and it also depends on the host animal’s innate and
acquired immunity.
Vaccine immunity persists via
-Immunologic memory (B cells and T cells)
-Long lived plasma cells – memory
effector B cells – these cells are present in the bone marrow
-Long lived memory effector T cells
-Innate (age) and acquired immunity
Duration of Immunity after vaccination in general is much
longer for viruses than for bacteria. For systemic than for a
local mucosal infection or disease. For modified live
vaccines.
Introduction of the vaccines for Canine Distemper and Canine
Adenovirus (hepatitis) in the 1960s led to a dramatic decrease in the annual
incidence of these diseases in the U.S. Canine hepatitis is
literally extinct in domestic canines in the US. However,
this must vaccine must still administered because wild animals still have canine
hepatitis and it helps reduce cases of bordatella.
Introduction of vaccines for Canine Parvovirus-2 led to a
dramatic decrease in the annual incidence of this disease in the US after
1978. There are still plenty of parvo outbreaks.
Changing Philosophy of Vaccination
Significant changes are continuing to occur within veterinary medicine’s
view of vaccination. A short time ago the common thought
was:
-Combination vaccines are easiest for owners
-If the vaccines don’t help, they won’t hurt.
-If annual revaccination is
recommended on the label, then we should vaccinate annually or more often,
regardless of immunity and duration of immunity of the vaccine.
New vaccine guidelines will be developed by specialty groups
like the AAFP, AAEP, AABP and the AAHA Canine vaccine Task Force rather than the
AVMA. Recommendations are available at the AAHA website: www.aahanet.org. These
were updated in 2006. The AAFP updated feline
recommendations.
What’s new?
1. Recommended/Core Vaccines – ALL dogs should receive CDV,
CPV-2, CAV-2 and rabies
-Interval should be 12 weeks, 16
weeks and then at one year (or one year after last vaccination) and then not
more often than every three years. Rabies administer at 3
months, at 1 year, followed by adult revaccination every three years.
-Minimum of immunity is at least 7-10 years
-Vaccinating more often than every three years adds no benefit
2. Optional/Non-core Vaccines – only used in dogs at risk or
under special circumstances. Examples include: Lepto,
bordatella, Lyme and CPI
Must be given at least yearly, some every six months
3. Not recommended vaccines – corona and giardia.
“Vaccines in search of a disease.” No need to give
these vaccines because they are killed vaccines and not effective.
In cats, the corona vaccine can actually cause FIP.
Methods Used to Determine DOI for Core Vaccines
- Challenge with virulent agents
There is a new study that is ready
to commence, to challenge the three year duration of immunity in the rabies
vaccine, the study must be regulated by the USDA. In the
control study, 80% of the dogs must die from rabies.
- serology – excellent relationship between antibody and
protection
- all canine core vaccines
- feline panleukopenia (parvo) virus
- rabies
- Serology does not correlate with protection from:
- Calicivirus
- Herpesvirus
All the major veterinary biologic companies have now reported
DOI studies for their products.
All companies have demonstrated a minimum DOI of 3 years or
longer for their core products.
Considerations in Assesing Risk Benefit of optional
vaccines
Parainfluenza
Leptospira bacterins
Bordetella
Borrelia burgdoreferi
Rattlesnake Vaccines
Periodontal Vaccines
Melanoma Vaccines
*never combine viral and bacterial vaccines, never vaccinate
for lepto before 12 weeks old.
Distemper, parvo, adeno1/adeno2 – 4 way
Distemper, parvo, adeno1/adeno2 & parainfluenza – 5 way
Antibody titer – Excellent correlations have been shown
between serum antibody and protection for the canine core vaccines.
-Yes – No tests, vaccinate all
“no” even though the dog may be immune. These are the easiest
to understand.
-% tests – give you numbers
-#s test – anything above the “less than” number the dog is immune.
Test for CDV and CPV-2 after puppy vaccination, take sample 2
or more weeks after the last puppy dose. If not immune,
vaccinate again.
*Titers not really needed as adults if practicing current
AAHA guidelines. However, veterinarians my use this as a
practice tool to get patients in annually for a physical examination.
Adverse reactions:
-Rare is less than 1 reaction per 10,000 animals
-Uncommon >/ 1 reaction per 10,000 but /<1 reaction per 1,000
animals
-Common >1 reaction per 1,000 animals
Rare vaccine reactions
Injection site sarcomas
Anaphylaxis
Arthritis, polyarthritis
–hypertrophic osteodystrophy
Autoimmune Hemolytic Anemia
Immune Mediated
Thrombocytopenia
Thyroidistis
Glomerulonephritis
Disease or Enhanced Disease which
the vaccine was designed to prevent
Myocarditis
Post Vaccinal Encephalitis or
polyneuritis
Seizures
Abortion, congenital anomalies,
embryonic/fetal death, failure to conceive
Moderate reactions
Immunosuppression
Behavioral changes – could be
transient
Vitiligo – loss of pigment
Loss of hair
Weight loss (cachexia)
Reduced milk production
Lameness
Granulomas/abscesses
Hives
Facial edema
Atopy – skin problems
Respiratory disease
Allergic uveitis (blue eye)
Mild reactions
Lethargy
Hair loss, hair color changes at
injection site
Fever
Soreness
Stiffness
Refusal to eat – transient
Conjunctivitis
Sneezing
Oral ulcers
*Pretreatment with benedryl or steroids can help if need to
vaccinate and adverse have occurred in the past.
Report adverse reactions to:
Manufacturer (you or your vet)
The USDA
Other (experts, vets, etc)
Legal aspects of vaccination
-The only vaccine required by law is rabies vaccine.
-All other vaccines for dog and cat can be given as often or
as infrequently as desired. Decision of the veterinarian
and/or owner.
-There is no label requirement and nothing official (USDA)
with regard to minimum DOI or frequency of vaccination.
** Vaccination is a medical decision that should entail the
same considerations and reasoning skills required when selecting an appropriate
medical care.
Vaccination prior to breeding is not necessary because
antibodies should also be there. It is better to titer
test. If you are going to do vaccinate a brood bitch it MUST
be done before she comes into season.
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