How Vaccinations Stimulate the Immune System

Each puppy and kitten receives maternal antibodies from the mother, both through the placenta and also in the colostrum (the first milk). This is termed “Passive Protection” and the strength of these antibodies is dependent upon the strength of the mother’s immune system. The mother obtains these antibodies from prior vaccination or by natural exposure to disease. Maternal antibodies are a two-edged sword; they may protect the puppy against disease early in life, but they also interfere/block the young animal’s response to vaccinations or active immunization. These maternal antibodies can interfere with vaccination for as long as 14 to 16 weeks in some puppies and kittens.

A refractory period can exist in some puppies or kittens where very low, almost undetectable levels of maternal antibody will inhibit the vaccination process, but will not protect the puppy/kitten from infection (from exposure to the natural virus). To determine the exact time at which this refractory period occurs is very expensive. Therefore, a SERIES of vaccinations is the most inexpensive and best way to protect puppies and kittens against disease, insuring vaccination at the best time. It is important to begin vaccinations at an early age and repeat every 3-4 weeks until the putty or kitten is at least 16-18 weeks old.

Immune System

Puppies and kittens in general do not have a very strong immune system. It can take pets up to 6 months or even a full year before their immune system is considered fully functional. Because of the interference from the maternal antibodies, veterinarians do not begin the vaccination series until the pet is six to eight weeks of age. The vaccines are then boostered at three to four week intervals until the pet is sixteen to eighteen weeks of age.

Because of the different strengths of response each puppy and kitten will have to vaccination, they can still be highly susceptible to infection until 2-4 weeks after the last injection of the immunization series.

Vaccines do not cause a disease, but act as a stimulus to your pet’s immune system, causing it to produce antibodies capable of protecting your pet against those specific diseases. Antibodies fight disease by killing disease-causing organisms within the body.

 

Health

The health of an individual’s immune system is dependent upon many variables. Like people, pets have varying abilities to respond to vaccines and fight off infections. Some scientific studies have demonstrated that some pets have a very strong immune response and may not need vaccinations on a yearly basis. This is very similar to how the human immune system works. However, other scientific studies have demonstrated that some pets never achieve complete protection (immunity) from certain diseases, even with repeated booster vaccinations.

Vaccines are not guaranteed to prevent disease because too many variables are involved. Very young puppies and kittens, as well as aging pets, appear to have diminished ability to respond to vaccinations. In such cases, it is critical that the pet be re-vaccinated at the appropriate interval. An animal that is underweight, pregnant, or stressed because of a serious infestation of parasites or other illness also may respond poorly to vaccination.

 

Potential Vaccine Reactions

There is less than 0.05 percent chance of a pet having an adverse reaction to a particular vaccine. This reaction is usually caused by the adjuvant which is in the vaccine to stimulate the immune system.

Common Reactions

Cats can have a severe, sometimes fatal, reaction to vaccinations. This type of reaction happens less than 0.05 percent of the time. They have an anaphylactic response—vomiting, diarrhea, salivating, and walking off-balance as if they were drunk. This response usually occurs within fifteen to thirty minutes, but we caution owners to observe their cat for a few hours after vaccination. Sometimes cats will just feel poorly and be lethargic the day following vaccinations.

Because of the potential severity of the reaction, our hospital does not change the type of dog and cat vaccines used. This way, we know how our pets will react based upon previous vaccination. However, we do like clients to observe their pets after each vaccination because occasionally the drug companies will improve (and therefore change) their vaccines.

Dogs can have three different types of vaccine reactions:

Anaphylactice response—what we like to call the collapsing puppy syndrome. This happens less than two percent of the time and is usually within ten to fifteen minutes.

Allergic response—with this reaction, the eyelids, nose, lips, and face puff up and the dogs get lumps (hives) all over their body. This reaction can occur within fifteen to thirty minutes, one to two hours later, or six to eight hours later. This reaction usually responds very well to Benadryl.

Delayed cellular response— lumps on your dog’s body can appear where vaccines are given. This lump may occur within one to three weeks of the vaccination, is usually non-painful and may take one to two weeks to go away.

Rare Reactions

Part of the controversy surrounding vaccines involves the possibility of vaccine associated tumors and auto-immune disease.

Feline Vaccine Associated Sarcomas first came to our attention over 20 years ago. It occurs in less than four in 10,000 cats from vaccinations (an injection of any type can potentially cause a sarcoma). It is now believed that there is a genetic component involved in development of the tumor.

Our hospital uses non-adjuvanted vaccines, which are less likely to cause reactions.  The diseases vaccinated for can lead to severe and even fatal consequences (for example, Feline Leukemia and Rabies).  The risk/benefit ratio of possible vaccine reactions must be weighed against the known risk of disease.  Vaccines are also recommended on an individual basis, resulting in fewer numbers of unnecessary vaccinations. For more information on this reaction, please refer to our Vaccines and Sarcomas Handout.

Autoimmune Disease

Autoimmune disease can occur in dogs for a number of reasons – genetic/hereditary, viral or bacterial infection, drugs, and vaccines. It is estimated to occur in less than four in 10,000 dogs because of vaccinations. Autoimmune disease can also be brought on by numerous causes other that just vaccines, so it is difficult to implicate vaccination as a definitive cause in these cases.  The diseases vaccinated for can lead to severe and even fatal consequences (for example, Parvo, Distemper and Rabies).  The risk/benefit ratio of possible vaccine reactions must be weighed against the known risk of disease.  Vaccines are also recommended on an individual basis, resulting in fewer numbers of unnecessary vaccinations.

 

Vaccine Protocols

Canines:

DHPPC—Distemper, Hepatitis, Parainfluenza, Parvovirus – This vaccine needs to be given as a part of the puppy series (booster vaccines 3 weeks apart from 6-18 weeks of age) and again at 12 months of age. It will then be given once every 3 years unless indicated otherwise based upon the needs of the pet.  It is required at our hospital for all boarding, surgical and dental patients.

Bordetella (Kennel Cough)—This vaccine is to be given at 3-4 months of age and boostered annually. It is required at our hospital for all boarding, surgical and dental patients.

Rabies—Per state law, this vaccine is to be given at 4 months of age, 12 months later and then every 3 years using a 3 year vaccine. Rabies is fatal not only to animals, but also to people!  It is required at our hospital for all boarding, surgical and dental patients.

Canine Influenza—Compared to the others, this is a relatively new disease.  There are two strains that are currently vaccinated for.  The vaccine is given two times (2-3 weeks apart) and then on an annual basis.  Recommendation of this vaccine depends upon your pet’s lifestyle and possible exposure to other dogs.  It is required at our hospital for all boarding patients.

Lyme—This vaccine is recommended annually for those dogs exposed to ticks. Not all dogs need this vaccine. It is our strong recommendation that all dogs at risk of exposure to ticks be placed on tick repellant/insecticidal products.

Leptospira—This vaccine is primarily recommended for hunting, working, and outdoor/rural dogs.  However, some indoor dogs have also gotten this disease.  Leptospira is contagious to people. Unfortunately this vaccine does not protect against all of the serovars (sub-types) of this disease and therefore your dog cannot be considered fully protected from this disease from vaccination alone.  Infection occurs after exposure to water contaminated with urine from infected wildlife.

Felines:

FVRCP—Feline Viral Rhinotracheitis, Calicivirus, Panleukopenia This vaccine is to be given to all cats every 3 years following their kitten series (booster vaccines 3 weeks apart from 6-18 weeks of age) and a booster every 3 years.  It is required at our hospital for all boarding, surgical and dental patients.

Rabies— according to state law, this vaccine is to be given to your pet at 4 months of age, 12 months later and then every 3 years using a 3 year vaccine or annually using a 1 year vaccine.  It is required at our hospital for all pets that are boarding, or have surgical or dental procedures.

FeLV—Feline Leukemia Virus This vaccine is recommended for all outdoor and indoor/outdoor cats on an annual basis following kitten series vaccinations.  After their initial kitten series, indoor cats and cats not exposed to indoor/outdoor cats do not need to receive this vaccine.

FIV—Feline Immunodeficiency Virus This vaccine is recommended for all outdoor cats and indoor/outdoor cats on an annual basis following kitten series vaccinations. Cats will need to be tested for FIV infection prior to vaccination.

Like any reputable hospital, we require vaccinations prior to boarding and surgery, but we do not require that patients get them from us. We’re happy to accept them from any licensed veterinarian/veterinary hospital.  We do not accept feed store or other vaccines given by non-licensed individuals.  We truly believe that regular vaccinations are extremely important in ensuring your pet’s well-being.

Other Protective Measures

Do not take your young puppy/kitten to the front yard, park, around the block, or to PetSmart or PetCo until he or she is 4-5 months old. These are all places where infectious animals can be or have been.

Only have the young puppy/kitten around adult animals that you know are current on vaccinations. There should be no contact with stray animals or animals that you are not sure of.

Do not let your puppy (kitten) be exposed to any other young puppies (kittens), even those coming to our hospital to receive vaccines. These animals could be incubating disease (and therefore be contagious) without showing any clinical signs of illness.

Always wash your hands after handling any animal.

Please do not hesitate to talk with one of our Doctors, should you have any concerns or questions.