The decision to vaccinate, even with core vaccines, should be based on a risk-benefit assessment for each cat and for each vaccine antigen. Benefits of vaccination should be balanced against the risk of adverse events, likelihood of exposure, and disease severity. Every effort should be made to ensure that cats are healthy before vaccination. However, concurrent illness (including retroviral infections) does not necessarily preclude vaccination.
AAHA/AAFP Feline Vaccination Guidelines Task Force
Core vaccines are for all cats with an unknown vaccination history. The targeted diseases cause significant morbidity and mortality and are widely distributed. In general, vaccination for core diseases results in good protection.
Core vaccines for shelter cats from the 2020 AAHA/AAFP Feline Vaccination Guidelines.
Non-core vaccines are optional vaccines that should be considered in the light of exposure risk; that is, based on geographic distribution and the lifestyle of the cat. Optional or non-core vaccines for cats include FeLV ( for cats older than 1 year ), Chlamydia felis , and Bordetella bronchiseptica vaccines.
Vaccines, including those from different manufacturers that are licensed to protect against the same pathogen, should not be assumed as equivalent. Differences in processes and technology used to produce vaccines, as well as additives such as adjuvants, and vaccine route of administration influence efficacy, safety, and duration of immunity. Vaccines may be inactivated, attenuated live, or recombinant.
The not generally recommended category of vaccines pertains to diseases of low clinical significance or that respond readily to treatment; vaccines for which evidence of efficacy in the field is minimal; or vaccines that may produce a relatively higher incidence of adverse events with limited benefit.
Active immunization, achieved through proper vaccination, plays a critical role in the control of infectious diseases, both for individual cats and for the cat population as a whole. Some vaccines also reduce the potential for spread of zoonotic infections to humans (e.g., rabies). The benefits of routine, widespread vaccination are clear: the incidence of serious disease caused by pathogenic organisms, such as feline panleukopenia virus (FPV), can be reduced dramatically when widespread vaccination is practiced. However, the quality of vaccine-induced immunity is influenced by the patient’s environment, the characteristics of the vaccine, the pathogen, and the patient’s immune competence. Accurate prediction of the outcome of vaccination or the likelihood of exposure to a pathogen is impossible. Therefore, it is important that veterinarians inform cat owners that vaccination is not a guarantee of protection.
Although the administration of biological products is never entirely free of risk, currently available feline vaccines have an excellent safety record. That said, the true prevalence of adverse reactions is likely to be underestimated owing to underreporting by both veterinarians and owners. 49 Therefore, it is important to report any known or suspected negative events associated with vaccination.
A veterinarian should assess every patient regardless of appointment type (wellness, acute care or follow-up visit) for current vaccination status based on age and lifestyle. Informed by this assessment, an individualized patient vaccination plan should be developed or modified and then discussed and agreed upon in collaboration with the cat owner.