2 cats cuddling

Kitten Vaccination Schedule

How To Give Your Kitten The Best Shot At Life

LAST UPDATED 24 October 2023

This article is written by Pet Circle veterinarian, Dr Brittany Ward BVSc

As a new kitten owner, the excitement of having a playful feline companion is unparalleled. But with this joy comes the responsibility of ensuring their well-being. One common concern is the array of infectious diseases that can threaten a kitten's health, especially in their vulnerable early stages of life.

Failing to vaccinate or not adhering to the recommended vaccination schedule can expose your kitten to severe, sometimes fatal, illnesses.

Fortunately, a clear and effective kitten vaccination schedule exists, tailored to give your young kitty the best shield against these threats. In this guide, we'll dive deep into the importance of adhering to this vaccination routine, breaking down each vaccine, its timing, and its significance, ensuring your kitten enjoys a happy, healthy start in its new home.

In this article, we'll discuss:

  1. The Role of Vaccinations
  2. Understanding the Vaccination Schedule
  3. Diving Deeper: The Types Of Vaccinations
  4. Why The Schedule Matters: Maternal Antibodies
  5. When Are Non-Core Vaccinations Recommended?
  6. The Role of Veterinarians In The Vaccination Process
  7. Post-Kittenhood: Continuing The Protection
  8. Addressing Vaccination Concerns
  9. The Role of Vaccinations

    close up of vet vaccinating cat

    Image by Freepik

    Vaccinations play a vital role in protecting kittens from potentially fatal respiratory diseases, including Feline Calicivirus, Feline Parvovirus and Feline Herpesvirus-1. Kittens are particularly susceptible to these diseases because of their naive, under-developed immune systems.

    Feline Calicivirus and Feline Herpesvirus-1 can initially present as nose and eye discharge, sneezing, nasal congestion, conjunctivitis and mouth ulcers, but can worsen to fever, lethargy, anorexia (inappetence) and enlarged lymph nodes.

    Feline Panleukopaenia (Parvovirus) affects rapidly dividing cells so it can diminish the immune system, cause depression, listlessness, vomiting and/or diarrhoea that may contain blood, dull coat, discharge from nose and eyes or sudden death.

    Vaccinations expose your kitten to a potentially harmful virus, but in a non-virulent form. This means it isn't able to cause disease, but your kitten will still produce an immune response. The immune system will then be prepared to react if your kitten is exposed to an infective form of the virus, preventing them from experiencing the symptoms above or significantly reducing the severity.

    Vaccination also plays an important role in herd immunity. When 70% of the cat population is vaccinated, it significantly reduces the susceptible pool and limits the spread of the disease amongst those that are unvaccinated - this includes any cats that cannot be vaccinated (e.g. those with autoimmune conditions), stray cats or kittens too young for vaccination. In some cases, vaccinating animals can play a vital role in protecting people from the spread of disease. Rabies vaccination is the prime example of a disease that pets are vaccinated for to protect their owners.

    Understanding the Vaccination Schedule

    Your kitten will typically require a course of 3 vaccinations at the following ages:
    • 6-8 weeks
    • 10-12 weeks
    • 16 weeks or older

    Kittens under 6 weeks of age are protected by maternal antibodies. We know that in most kittens maternal protection wanes between 6-16 weeks of age, but cannot determine exactly when this will be in the individual kitten. In order to ensure kittens are protected, the World Small Animal Veterinary Association recommends vaccinating every 2-4 weeks from 6 weeks of age until 16 weeks or older.

    Diving Deeper: The Types of Vaccinations

    vaccination vials and syringes

    There are three different categories of vaccinations that your cat may be able to receive: Core Vaccinations, Non-Core Vaccinations and Not Recommended. The available vaccinations in each species and country are divided into these three categories depending on how important they are.

    Core Vaccinations

    Core vaccinations are those that all cats are required to receive irrespective of circumstances or location. These are essential vaccinations that are chosen because they protect cats against severe, life-threatening diseases that are present globally.

    There are 3 core vaccinations for cats:
    • Feline Panleukopaenia (FPV) OR Feline Parvovirus
    • Feline Calicivirus (FCV)
    • Feline Herpesvirus-1 (FHV-1) OR Feline Rhinotracheitis Virus

    These core vaccinations are combined and administered in a single injection called an F3 Vaccination. The core vaccination is what your kitten will be administered with at their kitten vaccinations.

    Rabies vaccination is considered a core vaccination in countries where it is regularly occurring. It is not a core vaccination in Australia, rather it is 'not recommended'. If your kitten, or cat, is moving overseas, you will need to check that country's core vaccination requirements.

    Non-Core Vaccinations

    Non-core vaccinations are those that are required by cats whose location, environment and lifestyle put them at an increased risk of the disease. These vaccinations are optional, but your vet may recommend them for your cat if they are at risk.

    The non-core vaccinations available in Australia are:
    • Feline Leukaemia Virus (FeLV)
    • Feline Immunodeficiency Virus (FIV)
    • Chlamydia felis

    If your kitten receives an F4 Vaccination, it will usually involve two vaccinations and one of the above Non-Core Vaccinations will be included with the F3 Core Vaccines. An F5 Vaccination includes both FeLV and FIV.

    Not Recommended Vaccinations

    Vaccines considered 'Not Recommended' are those that are not present in your local area and your kitten is not at risk of. The aim is to provide as few vaccinations as is required, so these vaccinations would be given unnecessarily. As mentioned above, Rabies vaccination is not recommended in Australia as we do not have Rabies in our country.

    Why The Schedule Matters: Exploring Maternal Antibodies

    Most kittens receive protection until 6 weeks of age by maternal antibodies, but what does this mean?

    Antibodies are proteins forming part of the immune system that are produced to counteract a specific foreign particle, called an antigen. Viruses are a type of antigen that the body responds to and produces antibodies for. These antibodies will then respond and eliminate the virus before it causes illness if your cat is exposed again. Vaccination exposes your kitten to a dose of the virus that is not capable of causing illness, but will trigger the body to produce antibodies.

    A vaccinated queen will also carry these antibodies in her blood and they can be transferred to the kitten in-utero as well as via milk. Once in the kitten, they will exist within the kitten's blood and protect the kitten if they are exposed to the virus. However, these antibodies will not last forever, and start to wane in kittens after 6 weeks of age.

    While present maternal antibodies are capable of responding to the vaccination, preventing the kitten from producing their own long term immunity. The maternal antibodies present in most kittens will have waned sufficiently by 12 weeks of age so that they will be susceptible to the vaccination. However, they can persist in some kittens until 20 weeks of age.

    The only way to accurately determine how much maternal protection a kitten has is performing a blood test called a titre test. This test is a specialised test performed by laboratories and can often be expensive. Instead of doing this for every kitten, administering a series of vaccinations every 2-4 weeks is recommended to give your kitten the best chance of being vaccinated when their maternal antibodies wane so that there is no period of susceptibility to the disease.

    This is the reason why most kittens will receive a course of 3 vaccinations, 4 weeks apart, between 6 weeks of age and 16 weeks or older. High risk kittens, those that get sick, or those starting vaccination early may require more than 3 vaccinations, but this will be advised by your vet.

    When Are Non-Core Vaccinations Recommended?

    As mentioned above, non-core vaccinations are those that are only required by cats who are at increased risk of the disease. So how do you know if your kitten is at risk?

    Feline Leukaemia Virus (FeLV) vaccination is recommended in kittens less than 1 year old with outdoor access, or exposure to other cats (particularly outdoor cats), in any area where the disease is prevalent. Check with your regular vet if you are living in an area of high prevalence. Any kittens negative for FeLV can be vaccinated with two doses 2-4 weeks apart.

    Feline Immunodeficiency Virus (FIV) is transmitted by cat bites. This means outdoor cats and cats in multicat households are most at risk. Cats in areas when FIV is of high prevalence, with outdoor access, should be considered for vaccination. Chat to your vet about prevalence in your local area.

    Chlamydia felis vaccination is usually recommended for cats with outdoor access and exposure to other cats. This disease is treatable and non-life threatening, so not all vets will recommend this vaccination.

    The Role of the Veterinarian in the Vaccination Process

    A vaccination isn't just as simple as administering the injection and then leaving the clinic. Your Vet plays a bigger role in the consultation and vaccination process.

    When you first come into the consultation, your Vet will ask questions about your kitten's general health. They will also perform a physical examination, including taking your kitten's temperature. This is to ensure that your kitten is healthy before administering the vaccine.

    Vaccinations are designed to activate the immune system and produce antibodies, a process that typically takes 7-14 days to occur. If your kitten is unwell, their immune system is already working hard to get them feeling better. This means it has a reduced capacity to respond to the vaccine and it will likely be ineffective. Giving a vaccination to a sick pet may also reduce their capacity to respond to the illness affecting them, which could worsen symptoms. Thirdly, because the immune system is already activated and cannot respond as intended to the vaccination, an adverse or anaphylactic reaction to the vaccination may occur. So it is important that only healthy pets are vaccinated.

    Your veterinarian will also want to check your kitten's general well-being and lifestyle to ensure they are up to date with parasite prevention, on a high quality, age-appropriate diet and discuss desexing. They can also assess any behavioural problems you may be experiencing to assist with training suggestions.

    The final role that a veterinarian plays in your kitten's vaccination consultation is tailoring their vaccination schedule. Your vet will ask about your kitten's lifestyle and environment to determine if they require any non-core vaccinations, their suitability for vaccinations (e.g. kittens with auto-immune conditions may not be suitable for vaccination) and if they require more frequent vaccination. Kittens that are at high risk or those that have been unwell, may require vaccination every 2 weeks or those receiving the final vaccination before 16 weeks may require an additional vaccination. You can discuss your kitten's tailored vaccination schedule with your vet.

    Post-Kittenhood: Continuing the Protection

    To protect any kittens that may have still had maternal antibodies by the final vaccination at 16-20 weeks, a 12 month booster vaccination is recommended, unless otherwise advised by your vet. After which, a booster vaccination will be given every 12 months.

    Addressing Vaccination Concerns

    Are Vaccinations Safe?

    Yes, for the majority of cats and kittens, these vaccinations are safe. Products such as these must undergo extensive testing prior to being licensed in order to note common side effects and ensure the vaccine is safe for the majority of cats.

    Can Adverse Reactions Occur?

    Like any vaccination or treatment, the potential for adverse reactions can occur, however, adverse reactions are rare. It is recommended that Veterinarians report all adverse events and studies have shown that approximately only 0.52% of cats (52 in 10,000) experience side effects from the vaccination.

    What Adverse Reactions Occur?

    Common side effects can include:
    • Lethargy, Slight Fever, Mild Discomfort - The most common and resulting from activation of the immune system. Usually resolve within 1-2 days and often considered normal.
    • Localised Swelling - Localised to injection site, may be tender and disappears quickly. Shouldn't have signs of inflammation like growth, discharge or heat.
    • Cold Like Symptoms - This includes sneezing, coughing and a runny nose.
    • Inappetence - Usually only lasts 24 hours.

    More serious side effects that would warrant a vet visit include:
    • Vomiting
    • Diarrhoea
    • Facial Swelling
    • Hives
    • Facial or body itching
    • Breathing difficulties

    These side effects will resolve with treatment by your veterinarian. Adverse reactions are more common in kittens than adults.

    What Happens If My Kitten Has Had An Adverse Reaction Before?

    If your kitten has had a reaction to a vaccination in the past, then you may understandably be reluctant to revaccinate them. However,there is a protocol in place for how these cases will be handled.

    Kittens that experience adverse reactions to core vaccines, will still need these repeated. Your vet may recommend serological testing to determine your cat's level of immunity and only vaccinate them when immunity drops. They will also likely administer an antihistamine before the next dose to prevent the reaction occurring and then your cat should be monitored closely for the next 24 hours.

    Optional non-core vaccinations are not recommended to repeat following an adverse reaction.

    What Is An Injection Site Sarcoma?

    You may have heard the term Feline Injection Site Sarcoma (FISS) and be wondering if your kitten is at risk. A FISS is a type of malignant cancer that cats are prone to developing at the site where an injection has been administered in the past. These can follow any type of injection, not just vaccinations; including microchips, fluids and medications. Injection Site Sarcomas only occur in 1 out of 10,000 cats, so are extremely rare.

    Do Indoor Cats Need to be Vaccinated?

    The simple answer is yes. Core vaccinations are required by all cats, regardless of lifestyle.

    The diseases that these vaccinations protect against are highly contagious and can be transmitted by an infected cat in all excretions. Air-borne particles can travel several metres and the virus can survive in the environment for weeks. Even if your kitten stays inside the house, you could potentially touch a contaminated cat or environment and spread the virus to your kitten at home.

    Some of the viruses, notably Feline Herpesvirus-1, can also remain latent in carrier cats. These cats can shed the virus into the environment without showing any symptoms. Carries of Feline Calicivirus typically last a couple months, but can be lifelong. Feline Herpesvirus-1 is lifelong in all infected cats and can be contracted from an infected mother at birth. Cats with latent infections will often experience disease during times of stress.

    Can My Kitten Still Become Infected Even If They Are Vaccinated?

    Vaccinations aim to prevent disease and reduce the severity of illness, they do not stop your kitten or cat from becoming infected.

    Reasons why a vaccination may not be successful are due to there being various different strains of the virus, persistent maternal antibodies that may respond to the vaccine, if your kitten was unwell at the time of vaccination or if your cat was infected with 'Cat Flu' prior to administration of the vaccine.

    Further Reading

    Want to read more? Check out our other articles:

    New Kitten Guide

    Flea Tick Worming Guide For Cats

    Introducing A New Kitten To Your Family

    Biting, Scratching, Pooping: A New Kitten Training Guide

    What Is The Best Kitten Food?

    How To Find A Good Vet

    Shop All Kitten Supplies Now

    WSAVA Vaccination Guidelines
    AVA Policies: Vaccination of Dogs and Cats
    Chlamydial Infections of Cats - VIN
    Feline Calicivirus Infection
    Feline Panleukopenia
    Feline Herpesvirus Infection or Feline Viral Rhinotracheitis
    Why Can't My Pet Get Vaccinations If Sick?
    RSPCA - About Pet Vaccinations
    The Cat Clinic - Vaccinations in Cats
    PetMD - Possible Vaccine Reactions
    Argyle Vet - Side Effects to Vaccines in Dogs and Cats
    Adverse Post-Vaccination Reactions