Feline Vaccination

A veterinarian giving a cat a vaccine shot.

Feline vaccination is the administration of antigenic material (the vaccine) in cats to produce immunity to a feline disease. Vaccines can prevent or ameliorate the effects of infection by a pathogen. Currently, there are geographically defined core vaccines and individually chosen non-core vaccine recommendations for cats. In many areas, the core vaccines consist of a single combined FVRCP vaccine shot which protects against FVR (FHV-1), FCV and FPV. Most vaccination protocols recommend a series of vaccines for kittens, with vaccine boosters given at one year of age. Frequency of vaccination thereafter varies with exposure risk, the disease and vaccine type. Most vaccines are given by subcutaneous (under the skin) or intramuscular (into the muscle) injection. Respiratory tract disease vaccination may be given intra-nasally (in the nose) in some cases.

Vaccine immunogens may consist of killed or inactivated pathogens, bio-engineered pathogen proteins or polypeptides, or, increasingly rarely, modified-live virus. Most vaccines contain adjuvants designed to boost the immune response to the vaccines. Many adverse reactions are associated with reactions to these adjuvants.

Available vaccines

Vaccines against the following diseases are available:

Core

• Feline viral rhinotracheitis (FVR) is an upper respiratory infection of cats caused by feline herpesvirus 1 (FHV-1), of the family Herpesviridae. It is also known as feline influenza. FVR is very contagious and can cause severe disease, including death from pneumonia in young kittens. All members of the Felidae family are susceptible to FVR,
• Feline calicivirus (FCV)
• Feline panleukopenia (FPV) more commonly known as feline distemper is caused by the feline parvovirus, a close relative of canine parvovirus. It is not related to canine distemper. Panleukopenia is primarily spread through contact with an infected cat's bodily fluids, feces, or fleas.
• Rabies in cats is a fatal disease transmitted by the bite of an infected mammal, such as a dog, raccoon, bat, or another cat. Animals with rabies suffer deterioration of the brain and tend to behave bizarrely and often aggressively, increasing the chances that they will bite another animal or a person and transmit the disease. Rabies is rare in many developed countries with more than 99% of all human deaths from rabies occurring in Africa, Asia and South America which report thirty thousand deaths annually.

Non-core

• Chlamydophila felis
• Feline leukemia virus (FeLV) is a retrovirus transmitted between infected cats when the transfer of saliva or nasal secretions is involved, for example when sharing a feeding dish. If not defeated by the animal’s immune system, the virus can be lethal. The disease is a virus, not a cancer. The name stems from the fact that the first disease associated with the virus was a form of leukemia. By the time it was discovered that the virus was not the same as leukemia, the misnomer had already found its way into the vocabulary of pet owners.
• Feline immunodeficiency virus (FIV), commonly known as Feline AIDS is a lentivirus that affects domesticated housecats worldwide. FeLV and FIV are in the same biological family, and are sometimes mistaken for one another. However, the viruses differ in many ways. Although many of the diseases caused by FeLV and FIV are similar, the specific ways in which they are caused also differs. However, a vaccine against this disease is not available in all countries.
• Bordetella

Not recommended

The following vaccines are not recommended by the American Assiociation of Feline Practitioners (AAFP) Feline Vaccine Advisory Panel due to either lack of evidence for effectiveness or high chance of adverse reaction.

• Feline infectious peritonitis (FIP)' is a fatal, incurable disease caused by Feline Infectious Peritonitis Virus (FIPV), which is a mutation of Feline Enteric Coronavirus (FECV/FeCoV). The mutated virus has the ability to invade and grow in certain white blood cells, namely macrophages. The immune system's response causes an intense inflammatory reaction in the containing tissues. This disease is generally fatal. However its incidence rate is roughly 1 in 5000 for households with one or two cats.
• Giardia lamblia

Controversy

In recent years, vaccination has become a controversial topic among veterinarians and pet owners. Recent studies have demonstrated that many vaccines are effective for several years, despite the common practice of "boosting" vaccines every year. This has particularly been demonstrated for the feline panleukopenia vaccine. For this reason, the American Veterinary Medical Association (AVMA) and American Association of Feline Practitioners (AAFP) have developed vaccination guidelines recommending that FVRCP vaccinations generally be administered every 3 years, after completion of the kitten series of shots (which is needed due to maternal antibody interference).

Adverse effects

FVRCP vaccines have also come under scrutiny of late due to possible risks to long term health. A study at Colorado State University noted an association between vaccination with parenteral (injectable) FVRCP vaccinations and development of antibodies against feline kidney tissue. Antibody development is hypothesized to develop when the immune system reacts to protein contaminants from the cell line used to cultivate vaccinial viruses. The cell line in question, the Crandell-Rees Feline Kidney (CRFK) cell line, was derived from a cat kidney. It is currently unknown whether this antibody development can lead to renal disease, though a recent follow-up study demonstrated evidence of inflammation on re-biopsy samples from some of the study cats. Vaccine-associated sarcoma, a type of malignant tumor has also occurred in association with FVRCP vaccines, though feline leukemia virus (FeLV) and rabies virus vaccines are more commonly implicated.

Given the studies documenting long-term efficacy and the creation of vaccine guidelines by authoritative organization like the AAFP, many veterinarians have adjusted their vaccine schedules. Some practitioners offer blood tests that measure the cat's levels of protective antibodies to determine which cats need to be vaccinated more frequently. Due to the extremely deadly and contagious nature of panleukopenia, the AVMA and AAFP strongly advocate the appropriate use of vaccinations against panleukopenia.

In November 1996 Vaccine-Associated Feline Sarcoma Task Force (VAFSTF) was formed. The American Veterinary Medical Association (AVMA), the American Association of Feline Practitioners (AAFP), the American Animal Hospital Association (AAHA) and the Veterinary Cancer Society (VCS) cooperated to respond to an increased incidence of soft tissue sarcomas occurring at vaccination sites. Veterinarians are advised to inject vaccines into leg tissue. Owners are advised to monitor injection sites for signs of tumors and contact their veterinarian immediately if one develops.