Feline Vaccination Guide: Core & Non-Core Vaccines for Cats

Vaccination is a cornerstone of preventive veterinary medicine for cats. Vaccines stimulate the immune system to recognize and fight specific infectious agents, providing protection before a cat is ever exposed to disease. The goal is not only to protect the individual cat but also to reduce the overall prevalence of serious feline infectious diseases in the population.

The American Association of Feline Practitioners (AAFP) and the World Small Animal Veterinary Association (WSAVA) publish evidence-based vaccination guidelines that categorize vaccines as either core or non-core:

• Core vaccines protect against diseases that are widespread, severe, or pose a public health risk. They are recommended for all cats regardless of whether they live indoors or outdoors.
• Non-core vaccines are recommended based on a cat's individual risk factors, including lifestyle, geographic location, exposure to other cats, and local disease prevalence.

Your veterinarian will assess your cat's risk profile and recommend a vaccination plan tailored to your cat's specific situation. No two cats have exactly the same risk, so vaccination protocols should be individualized rather than applied as a one-size-fits-all schedule.

Core vaccines are recommended for every cat. The two core vaccine categories for cats are FVRCP and rabies.

FVRCP (Feline Viral Rhinotracheitis, Calicivirus, Panleukopenia)

This combination vaccine protects against three serious diseases:

• Feline viral rhinotracheitis (feline herpesvirus-1, FHV-1): Causes upper respiratory infection with sneezing, nasal discharge, conjunctivitis, and fever. Once infected, cats become lifelong carriers and may have recurrent flare-ups during stress.
• Feline calicivirus (FCV): Another common cause of upper respiratory disease in cats. Can cause oral ulcers, pneumonia, and in rare cases a severe systemic form (virulent systemic FCV). Multiple strains exist, so vaccination reduces severity but may not prevent all infections.
• Feline panleukopenia (feline parvovirus, FPV): A highly contagious and often fatal disease, especially in kittens. Attacks rapidly dividing cells in the intestines, bone marrow, and lymphoid tissue, causing severe vomiting, diarrhea, and immunosuppression.

FVRCP is available as both modified live virus (MLV) and killed (inactivated) formulations. MLV vaccines generally produce a faster and stronger immune response. The kitten series typically begins at 6 to 8 weeks of age, with boosters administered every 3 to 4 weeks until 16 to 20 weeks of age. A 1-year booster is given after the initial series, followed by revaccination every 3 years for adult cats.

Rabies

Rabies vaccination is required by law in most jurisdictions in the United States and many other countries. Rabies is a fatal viral disease that can be transmitted to humans, making it a critical public health concern.

Both 1-year and 3-year rabies vaccines are available for cats. The AAFP and the Vaccine-Associated Feline Sarcoma Task Force (VAFSTF) recommend non-adjuvanted recombinant rabies vaccines (such as PureVax) for cats whenever possible, due to the association between adjuvanted vaccines and injection-site sarcomas. The initial rabies vaccine is typically administered at 12 to 16 weeks of age, with a booster 1 year later, then every 1 or 3 years depending on the product used and local regulations.

Non-core vaccines are administered based on a cat's individual risk assessment. Your veterinarian will consider your cat's age, lifestyle, health status, and potential for exposure when making recommendations.

Feline Leukemia Virus (FeLV)

FeLV is a retrovirus that suppresses the immune system and can cause anemia, lymphoma, and other cancers. It is spread through prolonged close contact, mutual grooming, shared food and water bowls, and from mother to kittens.

The AAFP recommends FeLV vaccination for all kittens regardless of planned lifestyle, since future risk may change. The initial series consists of 2 doses given 3 to 4 weeks apart, starting as early as 8 weeks of age. For adult cats, annual FeLV boosters are recommended for those at ongoing risk: outdoor cats, cats in multi-cat households with FeLV-positive members, and cats with access to unknown cats.

All cats should be tested for FeLV before initial vaccination to establish their status.

Feline Immunodeficiency Virus (FIV)

An FIV vaccine was previously available in North America, but it was discontinued in 2017. The vaccine had several limitations, including interference with FIV diagnostic testing (vaccinated cats would test positive, making it impossible to distinguish vaccinated from infected cats) and incomplete protection against all FIV subtypes. There is currently no commercially available FIV vaccine.

Chlamydia felis

The Chlamydia felis vaccine may be recommended for cats in multi-cat households or catteries with documented chlamydial infections. The bacterium causes conjunctivitis and mild upper respiratory signs. The vaccine reduces severity of disease but does not completely prevent infection.

Bordetella bronchiseptica

Bordetella bronchiseptica vaccination is sometimes recommended for cats in shelters, boarding facilities, or other high-density housing situations. An intranasal formulation is available. This vaccine is generally not necessary for pet cats in typical household settings.

The following schedule is based on current AAFP guidelines. Your veterinarian may adjust timing based on your cat's individual circumstances.

Kitten Series (Starting at 6 to 8 Weeks)

Age	Vaccines
6 to 8 weeks	FVRCP (first dose), FeLV (first dose)
9 to 12 weeks	FVRCP (second dose), FeLV (second dose)
12 to 16 weeks	FVRCP (third dose), Rabies (first dose)
16 to 20 weeks	FVRCP (fourth dose if series started before 6 weeks or if additional booster recommended)

The final FVRCP dose should be given at or after 16 weeks of age to ensure the kitten's maternal antibodies have waned enough for the vaccine to produce a strong immune response.

1-Year Boosters

All kittens should receive a 1-year booster for FVRCP and rabies approximately 12 months after completing the initial kitten series. FeLV should be boosted at 1 year if the cat remains at risk.

Adult Maintenance Schedule

• FVRCP: Every 3 years after the 1-year booster
• Rabies: Every 1 or 3 years depending on the vaccine product used and local law
• FeLV: Annually for at-risk cats (outdoor access, multi-cat households with unknown status cats)

Late-Start Protocol for Adult Cats with Unknown History

Adult cats with no known vaccination history should receive 2 doses of FVRCP given 3 to 4 weeks apart, followed by a booster in 1 year, then every 3 years. Rabies is given as a single initial dose with a booster in 1 year, then per product label. FeLV testing should be performed before FeLV vaccination, with 2 doses 3 to 4 weeks apart if the cat tests negative and is at risk.

Feline injection-site sarcoma is a rare but serious complication associated with vaccination and other injectable products in cats. These tumors are typically fibrosarcomas that develop at or near previous injection sites. The estimated incidence is approximately 1 to 10 cases per 10,000 vaccinated cats, though exact rates remain difficult to determine.

The Vaccine-Associated Feline Sarcoma Task Force (VAFSTF), formed jointly by the AVMA, AAFP, and other organizations, has studied this issue extensively. Key findings and recommendations include:

• Adjuvanted vaccines (which contain immune-stimulating additives) have been more strongly associated with sarcoma development than non-adjuvanted vaccines, though sarcomas have occurred with all types of injectable products including non-adjuvanted vaccines, long-acting antibiotics, and even microchips.
• Non-adjuvanted vaccines are preferred for cats whenever available. Products such as the recombinant rabies vaccine (PureVax) and non-adjuvanted FVRCP formulations are specifically designed to reduce this risk.
• Vaccination site recommendations have changed significantly. The VAFSTF recommends administering vaccines as distally on the limb as possible (rather than between the shoulder blades) so that if a sarcoma develops, surgical excision with wide margins or limb amputation is feasible.
• Current site guidelines: rabies in the right rear limb, FeLV in the left rear limb, and FVRCP in the right front limb, all given as distally as practical.

The 3-2-1 Rule

Cat owners should monitor injection sites and alert their veterinarian if any lump:

• Is still present 3 months after vaccination
• Is larger than 2 centimeters in diameter
• Is growing 1 month or more after vaccination

Any lump meeting these criteria should be biopsied promptly. Early detection and aggressive surgical treatment significantly improve outcomes. Injection-site sarcomas are locally invasive and can recur if not excised with wide margins, but they can be cured when caught early and treated appropriately.

Certain groups of cats require modified vaccination approaches:

Indoor-Only Cats

Even cats that never go outdoors still need core vaccines (FVRCP and rabies). Indoor cats can be exposed to viruses tracked in on shoes and clothing, through open windows or doors, during escapes, or through contact with new cats entering the household. Rabies vaccination is required by law in most areas regardless of lifestyle. Non-core vaccines such as FeLV may not be necessary for strictly indoor cats with no exposure to cats of unknown status, but your vet can help assess the true risk.

Shelter and Rescue Cats

Shelters often use modified protocols that prioritize rapid protection in high-risk environments. Intranasal FVRCP vaccines may be used because they produce mucosal immunity faster than injectable vaccines. Shelters typically vaccinate on intake regardless of prior history, and kittens may receive their first vaccines as early as 4 to 6 weeks in outbreak situations. Foster caregivers should follow the shelter's vaccination protocol and bring records to the adopter's first veterinary visit.

Pregnant Cats

Modified live virus (MLV) vaccines should generally be avoided in pregnant cats because they carry a theoretical risk of causing disease in developing fetuses. If vaccination is necessary during pregnancy, killed (inactivated) vaccines are preferred. Ideally, queens should be up to date on all vaccines before breeding.

Immunocompromised Cats

Cats with suppressed immune systems due to illness, chemotherapy, or high-dose corticosteroid therapy may not mount an adequate response to vaccination. Modified live vaccines may pose a risk of causing disease in severely immunocompromised cats. Vaccination decisions should be made on a case-by-case basis with your veterinarian.

FeLV-Positive and FIV-Positive Cats

Cats positive for FeLV or FIV can and should still receive killed (inactivated) core vaccines. Modified live vaccines are generally avoided in these cats due to the theoretical risk of vaccine-induced disease in immunocompromised individuals. The benefits of vaccination typically outweigh the risks, as these cats are more vulnerable to secondary infections.