Contributors: Richard B Ford, Michael Day

 Species: Feline   |   Classification: Miscellaneous

Introduction

  • Vaccination is an essential part of a healthcare program for domestic pets. The ideal strategy maximizes beneficial effects of vaccination while minimizing risks. This means ensuring each individual receives only the most appropriate vaccines, and that these vaccines are effective.
  • The immunogenicity of vaccines can be compromised by poor storage or inappropriate administration. In order to maintain efficacy vaccines must be stored in appropriate conditions:
    • Store under refrigeration at 2-8°C .
    • Do not freeze.
    • Protect from light.
    • Avoid prolonged or repetitive exposure to high ambient temperatures.
    • Once reconstituted (converted from dry to liquid form), vaccine should be used within 1 hour or it should be discarded)
  • The potency of many vaccines can be reduced by exposure to high temperatures for just a few hours.All vaccines should be stored in the refrigerator until used.
  • The technique of vaccination is also important, eg the skin should not be cleaned with disinfectants before injection. 
  • Only administer vaccine by the route(s) recommended by the manufacturer. Some agents given by the incorrect route may cause clinical disease, eg intranasal Bordetella bronchipseptica vaccine administered subcutaneously.
  • Several types of vaccines are available for protecting cats against various bacteria and viruses that cause infectious respiratory disease. Intranasal vaccines are available that provide rapid onset of immunity against both bacterial (Bordetella bronchiseptica) and viruses (feline herpesvirus-1 and calicivirus in the USA). The specific vaccine selected for administration should be determined by the risk for exposure unique to the individual cat.
  • The immune competence of the individual cat receiving vaccination is important in ensuring a protective immune response results from vaccination. Immunogenicity of a vaccine can be affected by poor health/nutrition, concurrent drug therapy, eg immunosuppressive agents, and stress.
  • For all vaccinations there are a number of important considerations to maximize vaccine efficacy while reducing risk of adverse effects:
    • Vaccinate healthy animals only.
    • Avoid vaccinating pregnant animals unless specifically indicated by manufacturer's datasheets.
    • If a pregnant queen must be vaccinated, use of inactivated (killed) vaccine is recommended.
  • In any population of animals, even with the strictest attention to correct administration, a small number of individuals may fail to respond to any vaccine. This is often genetically determined and such individuals are characterized as either 'low responders' or non-responders' to that particular antigenic component.
  • Chronic inflammation is one likely contributing factor in the development of feline injection site sarcoma Feline injection-site associated sarcoma (FISS). Veterinarians are encouraged to avoid use of adjuvant-containing vaccine that may induce a chronic inflammatory reaction at or near the injection site and to consider carefully the sites of injection for cats.

Protocol factors

Before vaccination consider:

  • The vaccine itself, ie which vaccines are indicated at which stage of life.
  • The environment for which a vaccine is most appropriate, eg catteries, animal shelters, household pets etc. Adult cats are classified (for the purposes of vaccination) as 'low' or 'high' risk. Low-risk cats are solitary, indoor-only animals that are not boarded. High-risk cats are indoor-outdoor cats, cats in multicat households or cats that are regularly boarded. Most UK cats will be considered 'high risk'.
  • Vaccination protocol, timing, boosters, age, route of administration (intranasal, SC, etc).
  • Known vaccine adverse reactions.

Note:

  • Kittens should be vaccinated against the core (major) infectious diseases - feline herpesvirus-1 Feline herpesvirus disease, calicivirus Feline calicivirus disease, feline parvovirus (feline panleukopenia) Feline panleucopenia virus disease beginning by 8 weeks of age, but not less than 6 weeks of age.Kittens should be vaccinated at intervals of 2-4 weeks until 16 weeks or older to avoid vaccine interference from Maternally-Derived Antibody. 
  • In the UK, vaccination against rabies Rabies is only carried out for cats travelling under the Pet Travel Scheme (PETS) Pet travel scheme.

Vaccines by indication

See Feline vaccination - initial series table Feline vaccination table.

Feline parvovirus (panleukopenia)

  • The feline parvovirus (FPV, or feline panleukopenia virus) vaccine is produced from virus grown in cultured cell lines.
  • Two types of feline parvovirus (FPV, or feline panleukopenia virus) vaccines are available:
    • 1. Attenuated (modified-live) virus available as a lyophilized (ie freeze-dried), non-adjuvanted product that must be reconstituted with an appropriate diluent prior to use, or
    • 2. Inactivated (killed) virus available as a liquid product that contains adjuvant. It is recommended that attenuated, combination FPV vaccines be administered within 1 hour following reconstitution or the dose should be discarded.
  • Attenuated (modified live virus, MLV) FPV vaccines are more immunogenic and less inflammatory than adjuvanted, inactivated (killed) vaccines. Attenuated vaccines are generally recommended over inactivated vaccines.
  • Inactivated (killed) FPV vaccines are only indicated for administration to pregnant queens and cats known to be retrovirus positive (FeLV and/or FIV).
  • In some countries, intranasal FPV (modified-live virus) vaccines are available.
  • Intranasal FPV vaccines may not be as effective as parenterally administered vaccines, especially in cats with concurrent upper respiratory signs (nasal mucus discharge/sneezing). It is recommended that cats receiving intranasal FPV vaccine also receive a dose of FPV vaccine labelled for parenteral administration to insure protection against this serious systemic infection.
  • Vaccination against FPV is indicated for all cats (core vaccine). All cats are potentially at risk of infection although disease is most severe in kittens.
  • Breeding queens should be vaccinated before mating to provide good early immunity in kittens through materally-derived antibody (MDA).Do not administer a MLV FPV vaccine to pregnant cats or to kittens less than 6 weeks of age due to the risk of causing cerebellar hypoplasia Cerebellum: hypoplasia (feline panleukopenia related) in the unborn kittens.

Protocol

  • FPV vaccine is typically administered in combination with feline herpesvirus-1 (FHV-1) and feline calicivirus (FCV) core vaccines. 
  • The initial vaccination series using the combination product should begin at 8 to 9 weeks of age, but not earlier than 6 weeks of age. Vaccine is given every 2-4 weeks until 16 weeks of age or older.
  • All parenteral FPV vaccines should be administered by the subcutaneous (SC) route. Intramuscular (IM) vaccination is not recommended.
  • A booster dose should be given within 1 year following the last dose in the initial series. WSAVA guidelines (2016) encourage this to be administered at 26 weeks of age rather than at 52 weeks of age or 52 weeks after the anniversary of the final vaccine in the early life series.
  • Subsequently, adult cats may be vaccinated with a single dose no more frequently than every 3 years. 
  • OVERDUE for BOOSTER VACCINATION: cats that have not received a booster inoculation within the past 3 years can be effectively boosted following administration of a single dose. It is not necessary to re-initiate a series of FPV vaccines in cats that are overdue for a booster. Serological testing Serology can be used to inform decision making about FPV vaccination in adult cats. Seropositive cats are protected and do not necessarily require revaccination. Note: serological testing applies only to FPV and NOT to FCV and FHV-1.

Feline Herpesvirus-1 and Feline Calicivirus

  • Today, feline herpesvirus-1 (FHV-1) vaccine and feline calicivirus (FCV) are administered as core vaccines in combination as an FHV-1 + FCV vaccine. The FHV-1 + FCV combination is most commonly administered in combination with FPV, although a stand-alone 2-way product is also available in many countries. Additional non-core vaccines (Chlamydia and FeLV) may also be combined with the core FHV-1 + FCV + FPV vaccines depending on the manufacturer.
  • FHV-1 + FCV vaccines are available as modified-live (MLV) (also called attenuated) or killed (also called inactivated). MLV FHV-1 + FCV vaccines are available in some countries for parenteral and intranasal administration. These products are not interchangeable and must be administered in accordance with the manufacturer's recommendation.
  • All killed FHV-1 + FCV vaccines must be administered parenterally. Most, but not all, killed FHV-1 + FCV vaccines contain adjuvant.
  • It is recommended that MLV FHV-1 + FCV vaccines be administered within 1 hour following reconstitution or the dose should be discarded, regardless of the administration route.
  • Non-adjuvanted, MLV (attenuated) and adjuvant-containing inactivated (killed) FHV-1 vaccines are available for parenteral administration.
  • In some countries, intranasal FHV-1 + FCV vaccines are available. Intranasal vaccine may be administered into one or both nostrils. Intranasal vaccines provide both local and systemic immune responses; however mild upper respiratory disease signs may be seen following intranasal administration, particularly in kittens.
  • MLV (attenuated) FHV-1 vaccines are more immunogenic and induce less inflammation at the injection site compared to adjuvant-containing killed (inactivated) vaccines. When feasible, the use of a MLV FHV-1 + FCV vaccine is recommended.
  • FHV-1 + FCV vaccines, regardless of the vaccine type or administration route, induce a "non-sterile" immune response, ie vaccinated cats may still become infected if exposed and can shed virulent virus into the environment.  Vaccinated cats are protected against developing severe clinical disease. Vaccination may not prevent development of a chronic carrier state.
  • Administration of core FHV-1 + FCV vaccine is indicated for all cats. All cats are potentially at risk of infection although clinical disease is most severe in kittens.
  • Breeding queens may be vaccinated prior to mating to boost antibody levels that will be passed to kittens during nursing (maternally derived antibody, or MDA).

Protocol

  • FHV-1 + FCV core vaccines are typically administered in combination with feline parvovirus core virus vaccine.
  • All parenteral FHV-1 + FCV vaccines should be administered by the subcutaneous (SC) route. Intramuscular (IM) vaccination is not recommended.  
  • The initial vaccination series using the combination product should begin at 8 to 9 weeks of age, but not earlier than 6 weeks of age. Vaccine should then be given every 2-4 weeks until 16 weeks of age or older.
  • A booster dose should be given within 1 year following the last dose in the initial series. WSAVA guidelines (2016) encourage this to be given at 26 weeks of age.
  • Subsequently, low-risk adult cats may be vaccinated with a single dose no more frequently than every 3 years. High-risk adult cats may benefit from annual revaccination with combination FHV-FCV vaccine.
  • For cats presented at 16 weeks of age, or older, an initial two-dose series (3 to 4 weeks apart) is recommended.
  • OVERDUE for BOOSTER VACCINATION:  cats that have not received a booster vaccine within the past 3 years can be effectively boosted following administration of a single dose. It is not necessary to re-initiate a series of FHV-1 + FCV vaccines in cats that are overdue.
  • Dual-Strain Feline Calicivirus Vaccines: conventional FCV vaccines have utilized the F9 strain of FCV. However, there is evidence to support that emergent FCV strains are more prevalent today and that conventional FCV vaccines may not protect cats today as well as they did several years ago. Efforts to improve the immunogenicity of FCV vaccines have resulted in the manufacture of dual-strain FCV vaccines. These vaccines contain a unique combination of two feline caliciviruses and are suggested to provide a greater level of protection against a virulent calicivirus challenge compared to a conventional, single strain (F9) vaccine. However, studies assessing the comparative efficacy of dual-strain FCV vaccines have not been published.

Rabies (Lyssavirus)

  • Commercially available feline non-core rabies vaccines are either adjuvanted, inactivated (killed) virus or non-adjuvanted, recombinant (virus vectored). Rabies vaccine may be sold as a 1-Year or a 3-Year product depending on the country of manufacture. Attenuated (modified-live virus) rabies vaccines are no longer available.
  • Vaccination requirements vary widely throughout the world. In countries deemed "rabies-free", administration of rabies vaccine may be restricted by law. Veterinarians are responsible for understanding and following applicable requirements/laws. The owner is responsible for complying with rabies vaccination requirements/laws. 
  • Administration of rabies vaccine has been causally linked to tumorigenesis (feline injection-site sarcoma, or FISS) in some cats. World Small Animal Veterinary Association Vaccination Guidelines recommend against the use of adjuvant-containing (inactivated or killed) vaccines in cats to minimize the risk of tumor development. 

Protocol

  • Where rabies immunization is required for cats, national, state, provincial, or municipal laws will dictate the earliest age rabies vaccine is to be administered. In most locations, rabies vaccine should not be administered to any cat less than 12 weeks of age. 
  • A single dose of rabies vaccine administered as early as 12 weeks of age is generally considered to provide protective immunity by 28 to 30 days following administration of the initial dose.
  • Cats imported into rabies-free countries or regions of the world may be required to show evidence of a positive fluorescent antibody virus neutralization (FAVN) titer prior to entry. The FAVN titer is only an indication of prior vaccination and is not considered to be index of protective immunity. 
  • In the US and Canada, a rabies antibody titer is not considered a legal index of immunity in lieu of re-vaccination. 
  • Cats older than 12 weeks only require a single dose.
  • Following administration of the first dose of rabies vaccine to a cat, a second dose should be administered within 1 year, regardless of the cat's age at the time the initial dose is administered.
  • Requirements dictating the intervals, and the type of vaccine used, for rabies re-vaccination is stipulated by the individual country (eg routine rabies vaccination of cats is not required in the UK).
  • Rabies vaccination can be given at the same time as routine vaccine protocols but vaccines must not be mixed in the same syringe.

Feline Leukemia Feline leukemia virus disease 

  • Non-core FeLV vaccines are available as either an adjuvanted, inactivated (killed) virus vaccines or as non-adjuvanted, recombinant (virus vectored) vaccine. Inactivated vaccines may be either whole virus or sub-unit vaccines.
  • In contrast to adult cats, kittens less than 6 to 8 months of age are at greatest risk for developing progressive FeLV-related disease if exposed. Therefore, it is recommended that kittens likely to become 'high-risk' adult cats be vaccinated against FeLV. 
  • Adult cats have less risk for developing progressive FeLV-related disease if infected. Vaccination of adult cats, therefore, should be based on known exposure risk. 
  • All cats should be tested for FeLV prior to vaccination.
  • Administration of adjuvanted FeLV vaccine has been causally linked to tumorigenesis (feline injection-site sarcoma Feline injection-site associated sarcoma, or FISS) in some cats. World Small Animal Veterinary Association Vaccination Guidelines recommend against the use of adjuvant-containing (inactivated or killed) vaccines in cats to minimize the risk of tumor development.
  • Non-adjuvanated recombinant vaccines have been shown to produce significantly less inflammation at the vaccination site when compared to adjuvanted killed vaccines.

Protocol

  • Two initial doses, 3-4 weeks apart, of FeLV vaccine are required to immunize, regardless of the vaccine type used. In kittens, the first dose should be administered not earlier than 8 to 9 weeks of age with second dose administered 3-4 weeks later. FeLV vaccine should be administered by the subcutaneous route.
  • A booster dose is recommended within 1 year following administration of the last dose in the initial series.
  • Subsequently, adult cats that have an on-going risk of exposure may be vaccinated with a single dose every 2-3 years.
  • OVERDUE for BOOSTER VACCINATION: at risk cats that have not received a booster inoculation within the past 3 years may benefit from administration of 2-doses, 3-4 weeks apart.

Feline Immunodeficiency Virus Feline immunodeficiency virus disease 

  • A non-core feline immunodeficiency virus (FIV) vaccine is available as an adjuvanted, inactivated (killed) whole virus vaccine comprised of isolates from two FIV clades (A and D) in some countries (not in Europe).
  • While the FIV vaccine contains clades A and D, the prevalence of individual clades varies by geographical region. In North America, clades A and B predominate with some clade C and F; in the UK, clade A predominates; and in Europe, clades A through D may be found with clade A predominant in northern Europe and clade B in southern Europe.
  • Efficacy of the FIV vaccine appears to be limited. Today, most authors, including the WSAVA Guidelines Group, do not recommend routine use of the FIV vaccine (non-core). 
  • The FIV vaccine has not been shown to extend the duration/quality of life when evaluated in long-term studies of FIV infected cats. 
  • If the veterinarian elects to vaccine a cat against FIV:
    • All vaccinates should be tested for FIV prior to vaccination.
    • The owner should be advised that vaccinated cats will have a positive FIV test on all commercial testing platforms. False positive test result can last for years. Discriminatory tests are available that can distinguish vaccinated from infected cats. 
    • All vaccinates should be microchipped for positive identification and association with a medical record that can verify prior vaccination. (This is to avoid the risk of a vaccinated cat being tested, found to be "positive" for FIV, and unnecessarily euthanized.)  
  • FIV is diagnosed in cats by detecting antibodies. Vaccinated cats may test positive for FIV for up to 4 years or more.
  • Additionally, kittens born of queens who have FIV or have been vaccinated for FIV, may receive FIV antibodies from colostrum (MDA). This may cause false positive test results until the cat is 5 to 6 months of age.

Protocol

  • When given, FIV vaccine is administered by the subcutaneous route, not earlier than 8 weeks of age.
  • Regardless of age, an initial three dose series (each dose 2-3 weeks apart) is required.
  • A booster dose is recommended within 1 year following administration of the last dose in the initial series.
  • Subsequently, adult cats that have an on-going high risk of exposure may be vaccinated with a single dose every year.

 Chlamydia felis (formerly called:  Chlamydia psittaci variant felis or Chlamydophila felis)   Chlamydia disease 

  • Non-core, non-adjuvanted avirulent live and adjuvanted inactivated (killed) C. felis vaccines are available for parenteral administration depending on the country. Avirulent live C. felis vaccines are more immunogenic and less inflammatory than adjuvanted inactivated (killed) vaccines and, therefore, are recommended.  
  • Regardless of the product used, C. felis vaccines will not prevent infection or shedding (non-sterile immunity). Rather, vaccines reduce the severity of clinical signs once a cat becomes infected.
  •  C. felis vaccine is non-core. Vaccination is indicated for cats known to have risk of exposure, and in those environments where the infection has been confirmed.  
  • When C. felis vaccine is given in combination with FPV, FHV-1 and FCV vaccine, an increased risk of post-vaccination reactions (lethargy, fever, anorexia, limb soreness) is expected.
  • Inadvertent ocular inoculation of avirulent live C. felis vaccine may cause signs of conjunctivitis.

Protocol

  • Typically administered in combination with FPV, FHV-1, and FCV, C. felis vaccines are administered not earlier than 9 weeks of age. All C. felis vaccines should be administered by the subcutaneous route.
  • Avirulent, live bacterial vaccines should not be administered to cats concurrently receiving antibiotic therapy. Doing so may render the vaccine antigen inactive. 
  • Regardless of age, an initial two dose series (3-4 weeks apart) is recommended.
  • Subsequently, adult cats that remain at risk of exposure may be vaccinated with a single dose every year.
  • OVERDUE for BOOSTER VACCINATION: at risk cats that have not received a booster inoculation within the past year may benefit from administration of 2-doses 2-4 weeks apart.

 Bordetella bronchiseptica  Bordetella bronchiseptica infection 

  • The feline Bordetella bronchiseptica (B. bronchiseptca) non-core vaccine is manufactured as an avirulent, live bacterial vaccine for intranasal administration only. 
  • Feline B. bronchiseptica vaccine is dispensed as a single dose vial and must be reconstituted prior to administration and should be used within 1 hour following reconstitution.
  • Vaccine indicated for intranasal administration MUST NOT BE ADMINISTERED PARENTERALLY.
  • Intranasal vaccine may be administered into one or both nostrils. 
  •  B. bronchiseptica vaccine is non-core and indicated for kittens/cats known to be at risk for exposure. All cats are potentially at risk of infection if exposed, however clinical disease is most severe in kittens.
  • Bordetella bronchiseptica may be transmitted between dogs and cats.
  • Cats vaccinated with B. bronchiseptica vaccine may shed the vaccine strain bacteria for 6 weeks and, rarely, up to a year.

Protocol

  • B. bronchiseptica vaccine may be administered to kittens as young as 4 weeks of age.
  • A single, initial dose is sufficient to immunize.
  • Avirulent, live bacterial vaccines should not be administered to cats concurrently receiving antibiotic therapy. Doing so may render the vaccine antigen inactive. 
  • Annual revaccination is recommended in cats with sustained risk for exposure.
  • OVERDUE FOR VACCINATION.  A single dose administered in accordance with the manufacturer's recommendations is sufficient to immunize regardless of the time elapsed since the previous vaccination.

Feline Infectious Peritonitis   Feline infectious peritonitis 

  • The feline infectious peritonitis (FIP) vaccine is manufactured as a modified-live virus vaccine for intranasal administration only.
  • FIP vaccine is dispensed as a single dose vial and must be reconstituted prior to administration and should be used within 1 hour following reconstitution.
  • Currently, the vaccine is only sold in the USA and Canada.
The vaccine is indicated for intranasal administration and MUST NOT BE ADMINISTERED PARENTERALLY.
  • Intranasal vaccine may be administered into one or both nostrils.  
  • The FIP vaccine is intended to prevent infection by the feline enteric coronavirus (FECV) which is a precursor to FIP. However, the vaccine is labelled for administration to cats 16 weeks of age and older. However, kittens housed in densely populated environments are at risk of exposure to FECV during first few weeks of life. 
  • Efficacy of the FIP vaccine appears to be limited. Today, most authors, including the WSAVA Guidelines Group, do not recommend use of the FIP vaccine. 
  • Optional: if the decision is made to administer the vaccine, the individual cat should be tested for FECV antibodies prior to vaccination. Cats that are FCoV negative at the time of initial vaccination may derive some benefit from vaccination. 

Protocol

  • FIP vaccine may be administered to kittens as young as 16 weeks of age.
  • Regardless of age, an initial two dose series (3-4 weeks apart) is recommended.
  • A booster dose is recommended within 1 year following administration of the last dose in the initial series.
  • Subsequently, annual revaccination is recommended in cats with sustained risk for exposure.

Virulent Systemic (Hypervirulent) Feline Calicivirus  Feline calicivirus (new strains) 

  • VS-FCV vaccine is an adjuvanted, inactivated dual-strain product dispensed in single dose vials which must be reconstituted prior to administration.
  • Currently, the vaccine is only available to veterinarians practicing in North America. 
  • Earlier studies demonstrated that individual outbreaks VS-FCV infection involved a novel mutation of FCV. Today, it is unknown whether the VS-FCV vaccine, made from early isolates, will be efficacious against future VS-FCV outbreaks.
  • Outbreaks of VS-FCV are rare and primarily occur in shelters and high-density multi-cat environments. Infections appear to be self-limiting, do not lead to development of a carrier state, and therefore appear not to have spread into the general cat population.
  • The VS-FCV vaccine is also marketed as a "Dual-Strain" FCV vaccine intended to provide a broader level of protection against FCV strains threatening cats today.  (See also: Dual-Strain Feline Calicivirus Vaccines above). 
  • The value of administering both a conventional FCV vaccine and the VS-FCV vaccine in protecting cats against other, emerging strains of respiratory FCV has been suggested but has not been demonstrated.

Protocol

  • VS-FCV vaccine may be administered to kittens as young as 6-8 weeks of age and then every 2-4 weeks until 16 weeks of age or older.
  • For adults, an initial two dose series (2-4 weeks apart) is recommended.
  • A booster dose is recommended within 1 year following administration of the last dose in the initial series.
  • Subsequently, annual revaccination is recommended in high-risk cats with sustained risk for exposure, but revaccination no more frequently than every 3 years for low-risk cats.
  • OVERDUE FOR VACCINATION: at risk cats that have not received a booster inoculation within the past 3 years may benefit from administration of 2-doses 3-4 weeks apart.

Dermatophytosis ("Ringworm")  Dermatophytosis  

  • Both monovalent (M. canis) and pentavalent vaccines for the prevention and treatment of feline dermatophytoses have been manufactured and sold in some countries. Lack of demonstrated efficacy ultimately led to removal of the monovalent vaccine from most markets.
  • Because there is limited evidence of any benefit for treating dermatophytosis and little evidence of efficacy in preventing infection, the dermatophytosis vaccine is generally not recommended. 
  • Because of the limited efficacy and lack of challenge studies on the use of these vaccines, routine vaccination of cats against dermatophytoses is not generally recommended. 

Protocol

  • Among cats selected for vaccination, three initial doses, administered at 2 week intervals (0, 14, and 28 days), by the intramuscular route, are recommended.
  • Subsequently, annual revaccination is recommended by the manufacturer in cats with sustained risk for exposure.