Cat vaccines are not one-size-fits-all. The 2020 AAHA/AAFP Feline Vaccination Guidelines and the WSAVA 2024 Vaccination Guidelines sort feline vaccines into core (recommended for all cats) and non-core (recommended based on lifestyle and risk). This article lays out the kitten vaccine sequence, explains which vaccines matter for indoor-only cats versus cats with outdoor access, covers FeLV risk stratification by age, and clarifies what adult boosters your cat actually needs and when.

Quick answer

Every cat should receive core vaccines: FVRCP (feline viral rhinotracheitis, calicivirus, panleukopenia), rabies, and FeLV (for all kittens under 1 year). Kittens start FVRCP at 6–8 weeks with boosters every 3–4 weeks until at least 16 weeks of age. Rabies is given once at 12 weeks or older. FeLV requires two doses, 3–4 weeks apart, starting at 8 weeks — but only after a negative FeLV test. After the kitten series, FVRCP is boosted at 1 year, then every 3 years. Rabies follows product label and local law (1-year or 3-year). FeLV boosters continue annually only for cats with ongoing outdoor exposure or contact with FeLV-positive cats.

Core versus non-core: what the guidelines actually say

The 2020 AAHA/AAFP Feline Vaccination Guidelines designate the following as core vaccines for all cats:

• FVRCP (feline herpesvirus-1, calicivirus, panleukopenia virus) — protects against three diseases that are widespread, highly contagious, and in the case of panleukopenia, often fatal.
• Rabies — required by law in most jurisdictions; protects against a fatal zoonotic disease.
• FeLV (feline leukemia virus) — core for all kittens under 1 year, regardless of indoor/outdoor status. After 1 year of age, FeLV becomes a non-core vaccine given only to cats with documented exposure risk.

Non-core vaccines include Chlamydia felis and Bordetella bronchiseptica, reserved for multi-cat environments where infection has been confirmed. The FIP (feline infectious peritonitis) vaccine is listed as "not generally recommended" by both AAFP and WSAVA due to questionable efficacy.

WSAVA's 2024 guidelines align closely: core vaccines are FHV-1, FCV, FPV, rabies, and FeLV (for young cats in endemic regions and at-risk adults). WSAVA emphasizes that FeLV vaccination should only follow a confirmed negative FeLV test.

Kitten vaccine schedule

Kittens receive maternal antibodies through their mother's first milk (colostrum). These antibodies gradually decline over the first weeks of life, but while present they can block vaccine response. The kitten series uses multiple doses to "catch" each kitten as maternal immunity wanes.

AAHA/AAFP notes that the final FVRCP dose should be administered at 16 weeks or older. If a kitten started the series late (e.g., a rescue kitten first seen at 12 weeks), two doses 3–4 weeks apart meet the minimum, provided the second dose is given at 16 weeks or older. Some veterinarians add a dose at 18–20 weeks for high-risk kittens, similar to the canine parvovirus protocol.

An intranasal FVRCP option exists. AAHA/AAFP notes that intranasal vaccines provide faster respiratory protection but do not protect against panleukopenia unless a parenteral (injectable) FPV component is included. Most practices use the injectable combination for the kitten series.

Indoor cats still need core vaccines

Indoor cats are not exempt from core vaccination. Here is why:

• Panleukopenia is caused by feline parvovirus, an extremely hardy pathogen that survives in the environment for months to years. It can be tracked indoors on shoes and clothing. It is often fatal in unvaccinated kittens.
• Feline herpesvirus and calicivirus cause upper respiratory infections. These viruses spread through aerosol droplets, shared bedding, and fomites (objects). An indoor cat can be exposed when a new cat enters the household, after a vet visit, or through an open window.
• Rabies is a legal requirement in most states regardless of indoor status. Bats — the most common source of rabies exposure for indoor cats — can enter homes through small openings. The CDC has documented rabies in indoor-only cats.
• FeLV is core for kittens because their immune systems are more susceptible, and because lifestyle can change. An indoor kitten may become an outdoor-access cat later in life.

The 2020 AAHA/AAFP guidelines state that core vaccines are recommended for all cats "with an unknown vaccination history," which includes indoor cats.

FeLV: why it is core for kittens and risk-based for adults

FeLV is transmitted through close contact: mutual grooming, bite wounds, shared food bowls, and from an infected queen to her kittens. The virus suppresses the immune system and can cause lymphoma, anemia, and bone marrow failure. Once infected, there is no cure.

AAHA/AAFP and WSAVA both recommend FeLV vaccination for:

• All kittens under 1 year of age, regardless of lifestyle.
• Adult cats with outdoor access, especially those with unsupervised outdoor time in areas where FeLV is endemic.
• Adult cats living with FeLV-positive cats.

The rationale for universal kitten vaccination: kittens are immunologically more susceptible to persistent FeLV infection than adults. Cornell University's Feline Health Center notes that the degree of virus exposure sufficient to infect 100% of young kittens will infect only 30% or fewer adults. One study found that 70% of kittens placed in a household with FeLV-infected cats became antigen-positive within five months. Even if a kitten is expected to be indoor-only, the guidelines recommend vaccinating because lifestyles change and the risk of exposure is highest in the first year.

Testing before vaccination is mandatory. FeLV vaccines do not treat existing infection. Vaccinating an FeLV-positive cat provides no benefit and wastes a dose. The guidelines recommend FeLV antigen testing (ELISA or other point-of-care test) before the first vaccine.

After the initial two-dose kitten series and the 1-year booster, FeLV becomes risk-based. Indoor-only adult cats with no contact with FeLV-positive cats generally do not need continued FeLV boosters. High-risk cats (outdoor access, living with FeLV-positive cats) should receive annual boosters; low-to-moderate-risk cats may be boosted every 2–3 years where product licensure allows.

Adult and senior cat boosters

After the kitten series is complete, adult cats move to a booster schedule:

For adult cats with unknown vaccination history, AAHA/AAFP recommends:

• FVRCP: Two doses of a modified-live injectable vaccine, 3–4 weeks apart, then a booster 1 year later, then every 3 years.
• Rabies: A single dose, followed by a booster 1 year later, then per label and law.
• FeLV: Two doses 3–4 weeks apart (after a negative test), then risk-based boosters.

Non-core vaccines

UC Davis School of Veterinary Medicine does not recommend routine vaccination of pet cats for Bordetella or Chlamydia unless there is a documented outbreak in a multi-cat environment. These vaccines do not provide complete protection and should be part of a broader infection control plan, not a standalone measure.

Vaccine-associated sarcoma: what to know

Feline injection-site sarcoma (FISS) is a rare but serious adverse event associated with injections in cats, including vaccines. Estimated incidence is 1–4 in 10,000 vaccinated cats. The 2020 AAHA/AAFP guidelines note that occurrence remains "infrequent and idiosyncratic."

To reduce risk:

• Many veterinarians use non-adjuvanted vaccines (such as PureVax products), which avoid the adjuvant carrier linked to increased local inflammation. WSAVA recommends non-adjuvanted vaccines when available.
• Vaccines are given in specific distal limb locations (e.g., left pelvic limb for FeLV, right pelvic limb for rabies) so that if a sarcoma develops, the limb can be amputated with a better chance of complete surgical excision.
• Injection sites should be monitored for lumps that persist longer than 3 months, grow larger than 2 cm, or increase in size 1 month after vaccination. The "3-2-1 rule" is the standard guideline for when to biopsy.

What to ask your veterinarian

• "Is my cat's FVRCP vaccine a 3-year product, and when is the next booster due?"
• "Does my cat need continued FeLV vaccination based on current lifestyle?"
• "Which rabies vaccine product do you use — 1-year or 3-year?"
• "Are you using non-adjuvanted vaccines?"
• "My cat is strictly indoor — does the core vaccine schedule change?"

These questions help align the vaccine plan with your cat's actual risk profile rather than defaulting to a one-size protocol.

What vaccines cost

Individual vaccine doses typically range from $25–60 each, plus the cost of the examination visit. A full kitten series (three FVRCP doses, two FeLV doses, and one rabies dose over three visits) generally totals $150–350 before exam fees. Many clinics offer wellness or vaccine packages that bundle the series at a lower total cost. Low-cost vaccine clinics (often run by shelters, humane societies, or mobile providers) may offer core vaccines at reduced rates.

Sources

• AAHA/AAFP Feline Vaccination Guidelines (2020): https://www.aaha.org/resources/2020-aahaaafp-feline-vaccination-guidelines/
• WSAVA Vaccination Guidelines (2024): https://wsava.org/wp-content/uploads/2024/04/WSAVA-Vaccination-guidelines-2024.pdf
• WSAVA Feline Vaccination Table (2025): https://wsava.org/wp-content/uploads/2025/06/Cats-Vaccination-Table.pdf
• UC Davis School of Veterinary Medicine, Vaccination Guidelines for Dogs and Cats: https://healthtopics.vetmed.ucdavis.edu/health-topics/feline/vaccination-guidelines-dogs-and-cats
• AAHA/AAFP Feline Vaccination Schedule for General Practice (PDF): https://www.aaha.org/wp-content/uploads/globalassets/02-guidelines/feline-vaccination-guidlines/feline-vaccine-table.pdf
• PetMD, Kitten Vaccination Schedule and Costs: https://www.petmd.com/cat/general-health/kitten-vaccination-schedule-and-costs