Do Adult Cats That Have Never Been Vaccinated Still Need a Series of Vaccines?

The simple answer to this question is yes.  Cats immune systems, like those of all animals, will create antibodies to the vaccines but these antibodies do not last forever and should be renewed on a regular basis.

Vaccines are important and are not only intended to protect the individual cat but also to protect the other cats in the area. It makes sense that if most of the cats in the area are vaccinated, there should be less chance of any disease spreading. One important thing that must be remembered is that even though a cat has been inoculated against a particular disease, it can still contract that disease.


Though this is often described as a failure of the vaccine, it really is a failure of the immune system of the cat. No vaccine will protect every individual to which it is given as so much depends on the immune system of the individual animal and its response to the vaccine.

If there is little or no response the animal will not be protected against the disease. Another factor that needs to be considered is the strain of the disease.  Not all vaccines protect against all strains of a disease.

Cat diseases

Cats should be vaccinated against the most common diseases. These include feline distemper, and serious infections that affect the lungs such as rhinotracheitis and chlamydia. Your local veterinary surgeon may recommend other vaccinations such as feline leukemia, and feline infectious peritonitis.


Also, depending on where you live, you may find a vaccination against rabies is also recommended. None of these vaccinations last indefinitely and many should be renewed on a regular basis, as recommended by the vet.

When you take the cat to the vet, you can expect that it will receive these vaccinations:

  • A distemper (panleukopenia) combination injection immediately. Another injection of the same vaccine should be administered 3-4 weeks later.  A booster should be given on an annual basis.
  • If you live in an area where feline leukemia is prevalent, the vet will recommend a test to see if the cat is free of the disease. If they are then the animal will receive a FeLV vaccination immediately and a further injection 3-4 weeks later.  This should be boosted on an annual basis.
  • If you live in an area where rabies is a possibility, the vet will administer the vaccination, and you will be advised of the booster intervals. There are legal requirements around rabies vaccinations, but they are usually biennial.

All responsible pet owners will ensure that their pets are inoculated according to a veterinarian’s recommendations.