Vaccine Protocol for Cats

Vaccine protocol seems confusing at times. I've always given two modified live virus three-way vaccines to kittens, giving the second between three and four weeks after the first. I do not use four-ways, which include protection against chlamydia because several vets have recommended against it, citing reaction to the vaccine by many cats and the short lived nature of any protection offered.

I was unsure, however, if adult cats need boosters if given a three-way, which provides protection against distemper (panoleukemia), herpes and calici. All three viruses are extremely common and very dangerous to cats especially those living in a shelter environment. Distemper can be brought into one's house on shoes or clothes and is long lived in the environment. I am fastidious about vaccinating any cat coming into my house immediately, against distemper. So far, I have not had a distemper outbreak among cats in my little shelter. (cross my fingers).

I believe it is a duty to vaccinate against rabies. I know there are people who do not believe in vaccination, but rabies has been controlled in this country largely because of vaccination. There have been several recent incidences in the Corvallis area of cats and dogs catching rabid bats, on the ground. The dog, who had not been vaccinated, had to be euthanized as a result. Many horrendous diseases worldwide have been nearly eliminated through vaccination. While someone may not believe in vaccinations, sometimes one must put their own beliefs aside for the greater good.

Over vaccinating, however, is a different story. So getting down the protocol is important and it can be confusing, because I have been told different things by different vets. The risk of injection site sarcoma due to vaccination in cats is strong and supports limiting vaccinations to the latest protocol available. For now, I believe it is the protocol below, but I have heard rumorings of more recent research making fewer vaccinations the protocol. I have put out some requests for information on the latest protocol and when available, I will post it.




Feline Vaccination Guidelines

In general, guidelines for vaccination of cats have been strongly influenced by the appearance of vaccine-associated sarcomas in cats, and in particular their epidemiologic association with feline leukemia virus vaccines and killed rabies virus vaccines. Thus, there is clear evidence for minimizing frequency of vaccination in cats. The recommendations below have been made in light of the AVMA/AAHA/AAFP/VCS task force recommendations on vaccine-associated sarcomas in cats. Risk factors for sarcomas should be discussed with cat owners at the time of examination. If a cat develops a palpable granuloma at the site of previous vaccination, the benefits vs risks of future vaccinations should be carefully considered. All vaccine-associated sarcomas should be reported to the vaccine manufacturer, the USDA Center for Veterinary Biologics, and the AVMA.

Feline Core Vaccines

The definitions of core and non-core vaccines described in the canine vaccination guidelines above also apply to the feline vaccines. The core feline vaccines are those for feline herpesvirus 1 (FHV1), feline calicivirus (FCV), feline panleukopenia virus (FPV) and rabies.

Feline Herpesvirus 1, Feline Calicivirus and Feline Panleukopenia Virus Vaccines

For initial kitten vaccination (< 16 weeks), one dose of parenteral vaccine containing modified live virus (MLV) FHV1, FCV, and FPV is recommended every 3-4 weeks from 6-8 weeks of age, with the final booster being given no sooner than 16 weeks of age. For cats older than 16 weeks of age, two doses of vaccine containing modified live virus (MLV) FHV1, FCV, and FPV given 3-4 weeks apart are recommended. After a booster at one year, revaccination is suggested every 3 years thereafter for cats at low risk of exposure. According to recommendations of the vaccine-associated sarcoma task force, these vaccines are administered over the right shoulder. Note that recommendations for killed and intranasal FHV1 and FCV vaccines are different from the above. Killed and intranasal varieties of these vaccines are not routinely used at the VMTH. The use of FPV MLV vaccines should be avoided in pregnant queens and kittens less than one month of age.

Feline Rabies Virus Vaccines

Cats are important in the epidemiology of rabies in the US. In general we recommend that kittens receive a single dose of killed or recombinant rabies vaccine at 12-16 weeks of age. Adult cats with unknown vaccination history should also receive a single dose of killed or recombinant rabies vaccine. For the recombinant vaccines, boosters are recommended at yearly intervals. We currently stock and suggest the use of the recombinant rabies vaccine, although there is no evidence as yet that it is associated with a decreased risk of sarcoma formation. For the killed rabies vaccines, a booster is required at one year, and thereafter, rabies vaccination should be performed every 3 years using a vaccine approved for 3-year administration. According to recommendations of the vaccine-associated sarcoma task force, rabies vaccines are administered subcutaneously as distally as possible in the right rear limb.

Feline Non-Core Vaccines

Optional or non-core vaccines for cats consist of the vaccines for feline leukemia virus (FeLV), feline immunodeficiency virus, virulent FCV, Chlamydophila felis, and Bordetella bronchiseptica.

Feline Leukemia Virus Vaccine

A number of FeLV vaccines are available on the market, and many have reasonable efficacy, although they do not produce sterilizing immunity. We suggest vaccination of FeLV-negative cats allowed to go outdoors or cats having direct contact with other cats of unknown FeLV status. Vaccination is most likely to be useful in kittens and young adult cats, because acquired resistance to infection develops beyond 16 weeks of age. As of 2006, the AAFP recommends primary vaccination of all kittens for FeLV, but the decision to administer booster vaccines is based on risk assessment. Vaccination is not recommended for FeLV-positive cats and indoor cats with no likelihood of exposure to FeLV. We currently stock and suggest the use of the recombinant transdermal FeLV vaccine, although there is no evidence as yet that it is associated with a decreased risk of sarcoma formation. Initially, two doses of vaccine are given at 2-4 week intervals, after which annual boosters are recommended depending on risk. According to recommendations of the vaccine-associated sarcoma task force, parenteral FeLV vaccines are administered subcutaneously as distally as possible in the left rear limb.

Feline Immunodeficiency Virus Vaccine

The FIV vaccine is an inactivated, adjuvented dual subtype vaccine that was released in July 2002. Unfortunately, vaccination of FIV-negative cats renders currently available serologic tests (ELISA and Western blot) positive for at least a year following vaccination, and polymerase chain reaction (PCR)-based tests do not reliably identify cats with natural infection. These PCR tests have yet to be standardized, and quality control may be problematic. Previous vaccination does not prevent infection, and the significance of a positive test result in a vaccinated cat cannot be assessed. Questions remain regarding the vaccine's ability to protect against all of the FIV subtypes and strains to which cats might be exposed. Therefore, the decision regarding whether to use this vaccine is not straightforward, and the risks and benefits of the use of this vaccine should be carefully discussed with owners prior to using the vaccine in cats at risk of exposure. The UC Davis VMTH pharmacy does not stock this vaccine, and its routine use in indoor cats is not recommended.

Feline Chlamydophila felis Vaccine

Chlamydophila felis causes conjunctivitis in cats that generally responds readily to antimicrobial treatment. Immunity induced by vaccination is probably of short duration and the vaccine provides only incomplete protection. The use of this vaccine could be considered for cats entering a population of cats where infection is known to be endemic. However, the vaccine has been associated with adverse reactions in 3% of vaccinated cats, and we do not recommend routine vaccination of low-risk cats with this vaccine. The Chlamydophila felis vaccine is therefore not stocked by the VMTH pharmacy.

Feline Bordetella bronchiseptica Vaccine

This is a modified live intranasal vaccine. Bordetella bronchiseptica is primarily a problem of very young kittens, where it can cause severe lower respiratory tract disease. It appears to be uncommon in adult cats and pet cats in general. For these reasons, the UC Davis VMTH does not recommend routine vaccination of pet cats for Bordetella bronchiseptica. The vaccine could be considered for young cats at high risk of exposure in large, multiple cat environments. The UC Davis VMTH pharmacy does not stock this vaccine.

Other Feline Vaccines

Feline Infectious Peritonitis Vaccine

The FIP vaccine is an intranasal modified live virus product. The efficacy of this vaccine is controversial, and duration of immunity may be short, although the vaccine appears to be safe. Although exposure to feline coronaviruses in cat populations is high, the incidence of FIP is very low, especially in single-cat households (where it is 1 in 5000). Most cats in cattery situations where FIP is a problem become infected with coronaviruses prior to 16 weeks of age, which is the age at which vaccination is first recommended. Vaccination could be considered for seronegative cats entering a cattery where FIP is common. We do not routinely recommend vaccinating household cats with the FIP vaccine, and the vaccine is not stocked by our pharmacy.

Feline Giardia Vaccine

A killed Giardia vaccine has been marketed for use in cats. This vaccine has the same limitations as those listed above for canine giardiasis, and has the additional potential to induce vaccine-associated sarcomas. We currently do not recommend routine use of this vaccine in pet cats. The UC Davis VMTH pharmacy does not stock this vaccine.