Sally Bahner
If there’s one key take-away from current feline vaccination protocols, it’s individualization.
Updated in conjunction with the American Association of Feline Practitioners (AAFP), the 2020 American Animal Hospital Association’s (AAHA) protocols reflect feline lifestyles and geographical locations.
“This important update provides veterinary practitioners the most current information to tailor vaccine recommendations to their individual patients,” says Amy E. S. Stone, VMD, Ph.D.,, Department of Small Animal Clinical Sciences, University of Florida, Gainesville, Florida. Dr. Stone chaired the guidelines task force.
Cats in the Clinic
Cat owners often perceive veterinarian visits in terms of vaccination needs and treatment of acute illnesses or emergencies. So if they have an indoor cat with little or no exposure to diseases addressed by vaccination, they may bypass the visit.
But the veterinary visit is an opportunity to discuss an overall strategy for a cat’s healthcare, addressing life stage, lifestyle, health, and the incidence of disease within the population.
The new guidelines include tables listing core and non-core vaccine recommendations, taking into account exposure risks for both pet and shelter cats. The publication updates the 2013 AAFP Feline Vaccination Report, reflecting recommendations from the 2016 WSAVA (World Small Animal Veterinarian Association) Guidelines for Vaccination of Dogs and Cats
Feline Vaccines 101
Vaccines come in three types – inactivated, attenuated live, and recombinant.
Inactivated vaccines are those in which the virus or source of the disease (termed “targeted pathogen”) is killed and can’t reproduce in the animal. They often contain adjuvants, which promote an adequate immune response, but have been know to cause adverse reactions in cats. Inactivated vaccines may have a shorter duration and may require more frequent boosters.
Attenuated (modified) live vaccines stimulate a response from the immune system similar to that occurring from natural infection and work more rapidly than inactivated vaccines. Partial immunity is rapid and the vaccine has live organisms that can protect other animals when shed. However, there is the potential for disease in animals who may be immunosuppressed.
Recombinant vaccines are created by manipulating the DNA of the disease resulting in a reduction of its virulence. The only recombinant vaccine available for cats in North America uses the “recombinant canarypox virus” as its means of transmission. They don’t need an adjuvant and there is less risk of injection-site sarcoma in cats. Some studies indicate the degree of protection may not be as robust.
Core vs. Non-Core
Recommended core vaccines for pet and shelter cats younger than 1 year old are FHV-1 (feline herpes type 1), FCV (feline calici virus), FPV (feline panleukopenia caused by feline parvovirus), rabies, and FeLV (feline leukemia).
In this update, the task force recommends additional vaccination at 6 months of age “to reduce the window of susceptibility in kittens with MDA – maternally derived antibodies – toward the end of the kitten series (16 to 18 weeks). Kittens absorb MDA through colostrum. They are most vulnerable to disease when that protection declines, usually at about the age of 1 month, although level of MDA is unpredictable and can sometimes last for weeks or months after that age.
The FHV-1, FCV, FVCCP vaccines are generally given after the age of 6 weeks, then 3 to 4 weeks later, until the age of 16 to 20 weeks. As stated above, revaccination is recommended at 6 months, then at 3 years. The first rabies vaccine is recommended at 12 to 16 weeks, then at 1 year, and 3 years thereafter; recommendations may vary according to state law.
Non-core vaccines, including FeLV (for cats older than 1 year), Chlamydia felis, and Bordetella bronchiseptica vaccines, are optional vaccines that should be considered in light of exposure risk, based on geographic distribution and the cat’s lifestyle.
The FIP vaccine (feline infectious peritonitis), delivered intranasally, is not generally recommended. Its efficacy is uncertain as are any risks and benefits.
All Cats Are Different
Pet cats living in a household with minimum outside exposure have less risk of exposure in contrast to cats in shelters, where there is a fluid population.
There is often a limited window for community cats, frequently given vaccinations in conjunction with the TNR – trap, neuter, return – process. They are typically at greatest risk for disease exposure.
Breeding cats living in a cattery also have greater risk of exposure to disease because they may be living together in large numbers. Queens must be optimally vaccinated to protect their kittens. Exposure risk also increases if a cat is being shown or if studs are brought into the cattery.
Finally, if foster cats (kittens or adults whose health history is unknown) are brought into a household, resident cats may need to be revaccinated to ensure their protection from disease.
Personalized Immunization Plans
Factors to consider for an individualized plan include age and life stage, disease susceptibility, whether immunity from the mother is still likely, activity level, and reproductive status.
Health status is also taken into account: the potential for disease, quality of nutrition, possibility of parasites, any congenital or chronic illnesses, including chronic stress, and potential immunodeficiency (a weakened immune system).
Location, lifestyle, and housing also play a role.
Studies have indicated duration of immunity greater than three years. That DOI does not apply to non-core vaccines, however. If required, they may be administered annually or even more frequently, depending on the vaccine.
Adverse Reactions
Owners worry about them, but postvaccination adverse reactions in cats are considered rare. The most commonly reported reactions are lethargy, anorexia, and fever, usually lasting for a few days. Owners may also note inflammation at the injection site.
The guidelines state that only a small percentage (0.52 percent) of cats experience reactions to vaccines within 30 days of the injection. Anaphylaxis is rare; signs include vomiting, diarrhea, respiratory distress, itching, facial swelling and collapse.
If a cat has experienced a reaction and needs to be revaccinated, a different vaccine formulation is recommended, along with premedication with an antihistamine. The cat should then be observed for several hours before going home.
Discuss potential reactions with clients, as well as the importance of vaccines. Responsible cat owners should be aware of which vaccines are important to their cats, based on age, lifestyle, and environment.
Other Reactions
Injection-site sarcomas may also occur. Although they were first identified in 1991, little is known about them. Generally, however, studies have shown that non-adjuvanted vaccines are less likely to result in injection-site sarcomas.
Incidence varies by country, depending on the types of vaccines used and population susceptibility.
“There isn’t very good data on the incidence of vaccine-related sarcoma,” says guidelines task force member Philip H. Kass, DVM, MPVM, MS, Ph.D., DACVPM, professor of analytic epidemiology, population health and reproduction (Veterinary Medicine), and Public Health Sciences (Medicine) at University of California, Davis.
The sarcomas are not reportable and are not always confirmed by a pathologist.
To improve the ability to treat the cat if an injection-site sarcoma develops, vaccination is recommended in the lower part of a limb. This enables clean margins in case amputation is necessary. The tail of the cat is also reported as a suitable site for vaccination, again toward the end in case amputation is needed. Practitioners are encouraged to keep detailed records regarding administration site.
This article was reviewed/edited by board-certified veterinary behaviorist Dr. Kenneth Martin and/or veterinary technician specialist in behavior Debbie Martin, LVT.
