Kittens are full of energy and curiosity—but their developing immune systems make them especially vulnerable to infectious diseases. Following a proper kitten vaccine schedule helps protect them from illnesses like feline distemper, feline herpes virus, and feline leukemia virus (FeLV).
At Hershey Veterinary Hospital, we tailor every kitten’s vaccination schedule to their unique needs and lifestyle, ensuring they stay healthy and protected as they grow.
Why Kittens Need Vaccinations
When kittens are born, they receive temporary antibodies from their mother’s milk. This protection fades after a few weeks, leaving them open to potentially life-threatening viruses and bacteria.
Vaccinations expose a kitten’s immune system to safe, inactive forms of disease, helping their body learn how to fight infections before real exposure occurs. This immunity is essential for both indoor and outdoor cats, as many viruses are airborne or can be carried indoors on shoes, clothing, or other pets.
Core Kitten Vaccines
Veterinarians classify vaccines as either core or non-core. Core vaccines are recommended for all kittens because they protect against the most common and dangerous diseases.
FVRCP Combination Vaccine
The FVRCP vaccine protects against three highly contagious viral diseases:
- Feline viral rhinotracheitis (feline herpes virus type-1): A major cause of upper respiratory infections and conjunctivitis in cats. Once infected, cats may carry the virus for life.
- Calicivirus: Causes respiratory illness, oral ulcers, and fever; it spreads quickly in multi-cat environments.
- Panleukopenia (feline distemper): A severe viral disease that attacks the immune system and digestive tract. It’s often fatal without immediate treatment.
Because FVRCP defends against multiple diseases, it’s often referred to as the combination vaccine or “distemper shot.” The FVRCP vaccine requires three initial doses spaced three to four weeks apart, then yearly boosters.
Rabies Vaccine
Rabies is a fatal viral disease that attacks the nervous system and can spread to humans. The Rabies vaccine is required by law throughout Pennsylvania and most of the U.S. Puppies usually receive it around 12–16 weeks of age, followed by a booster a year later, and then every one to three years depending on local laws.
Rabies vaccination protects not only your pet but also your family and community. Boarding facilities, groomers, and travel certificates all require proof of current rabies immunization.
Feline Leukemia Virus (FeLV) Vaccine
FeLV attacks the immune system and can lead to cancer, anemia, and other serious conditions. It’s transmitted through close contact such as grooming, bites, or shared bowls. The feline leukemia virus (FeLV) vaccine is strongly recommended for all kittens and for adult or outdoor cats that could be exposed to others.
The FeLV vaccine requires two initial doses spaced three to four weeks apart, then yearly boosters.
The Recommended Kitten Vaccine Schedule
Here’s the kitten vaccination schedule offered at Hershey Veterinary Hospital:
8 Weeks of Age
- FVRCP – Protects against Panleukopenia, Rhinotracheitis, and Calicivirus.
12 Weeks of Age
- FVRCP – Booster to reinforce immunity.
- FeLV – First dose of the Leukemia Virus vaccine.
16 Weeks of Age
- FVRCP – Final core booster.
- FeLV – Second Leukemia Virus booster.
- Rabies – First rabies vaccination (required by law).
16 Months and Yearly After
- FVRCP – Annual booster to maintain protection.
- FeLV – Booster for at-risk cats.
- Rabies – Annual rabies vaccination as required by local laws.
These vet visits are crucial to ensure vaccines are administered at the right time. Missing a booster may reduce your kitten’s immunity, so it’s important to stay on schedule.
Adjusting for Your Kitten’s Lifestyle
Not all cats face the same level of risk. Your veterinarian will assess your kitten’s lifestyle—whether they’re strictly indoors, spend time outdoors, or live with other pets—to determine the best vaccination plan.
For example:
- Indoor cats should still receive core vaccines, since some viruses are airborne or can be carried inside.
- Outdoor cats or those who socialize with other cats may need additional protection with more frequent FeLV boosters.
Discuss your kitten’s habits with your vet to create a plan that’s both safe and customized.
How Vaccines Work to Protect Your Kitten
Each vaccine introduces a harmless part of the virus into the body, prompting the immune system to build defenses. When your kitten later encounters the real pathogen, their body recognizes and fights it quickly.
This process strengthens their immune system and helps prevent the spread of highly contagious diseases in your community.
Possible Side Effects of Kitten Vaccines
Most kittens tolerate vaccines very well. Mild side effects may occur, such as:
- Temporary tiredness
- Mild soreness or swelling at the injection site
- A small, firm lump that fades within a few days
Severe reactions are rare. If your kitten experiences vomiting, swelling of the face, or difficulty breathing after vaccination, contact your veterinarian immediately.
Our team at Hershey Veterinary Hospital monitors every patient carefully and provides guidance for safe after-care following cat vaccinations.
When Do Adult Cats Need Boosters?
After your kitten completes their initial vaccine series, boosters are essential for maintaining immunity.
- FVRCP: Every one to three years, depending on your cat’s health and exposure risk.
- Rabies: Yearly, as required by Pennsylvania law.
- FeLV: Annually for cats that go outdoors or live with other cats.
Even adult cats with limited exposure benefit from regular vet checkups and boosters to ensure continued protection against viral disease.
Common Questions About the Kitten Vaccine Schedule
No. Even if your kitten never goes outside, viruses like feline herpes virus and calicivirus can be transmitted through open windows, on clothing, or from other pets. Core kitten vaccines are recommended for all kittens.
If a booster is delayed, your veterinarian may recommend restarting part of the vaccination schedule to ensure full immunity. Always call your vet before skipping or rescheduling a visit.
Kittens should remain indoors until seven to ten days after their final 16-week vaccines. Before then, they’re not fully protected from infectious diseases.
In their first year, kittens should visit the vet at least three to four times for vaccinations and general health checks. Regular vet visits help track your kitten’s growth, detect early health concerns, and reinforce positive handling experiences.
What to Expect at Each Vaccine Visit (and How to Prepare)
Each kitten vaccination appointment includes more than shots—we also do a full nose-to-tail exam to be sure your kitten is healthy enough for vaccines that day. We’ll check weight trends, hydration, eyes, ears, mouth, heart and lungs, and discuss any behavior or litter box changes since the last vet visit. If your kitten’s history is unknown, we may recommend FeLV testing before the first feline leukemia virus (FeLV) dose. For safety and tracking, our team follows standardized injection site locations for the FVRCP combination vaccine, FeLV, and rabies vaccination.
To make the day easier, bring your kitten in a secure carrier with a small blanket that smells like home. Jot down questions about diet, deworming, and parasite prevention—we’ll tailor advice to your kitten’s lifestyle (indoor only, supervised outdoor time, multi-cat home, etc.). After vaccines, mild sleepiness or tenderness is normal; offer water, a quiet space, and keep play low-key. If anything seems off—persistent vomiting, facial swelling, or trouble breathing—call us right away.
As your kitten grows into the adult cat stage, we’ll transition to the appropriate booster vaccination schedule for core kitten vaccines and discuss ongoing risk for outdoor cats. We’ll also help you keep records organized and set reminders so cat vaccinations stay on time, protecting your pet’s developing immune system from highly contagious infectious diseases like feline distemper, feline viral rhinotracheitis (herpes), and calicivirus.
Protecting Your Kitten for Life
Vaccinating your kitten is one of the most important steps you can take to safeguard their long-term health. By following the kitten vaccine schedule, you help protect your pet from painful, sometimes fatal illnesses—and ensure a healthier future.
Hershey Veterinary Hospital’s compassionate team will guide you through every stage of your kitten’s care, from first vaccines to annual wellness exams.
Request an appointment today to start your kitten on the right path. To learn more about all available pet vaccinations, explore our full list of preventive care services.
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