How Often Should Cats With FIV/Feline AIDS Receive Vaccines?


Dr. Barchas,

Appreciate your site greatly. Took in a stray kitten a couple months ago and found out he is FIV positive. Your information on FIV is immensely helpful and I am trying to spread the word that one does not have to euthanize or isolate an FIV positive cat. Thank you for the great information on this.

One question, though…should an FIV positive cat be given any vaccinations, considering the nature of his condition is a compromised immune system? It seems counter-intuitive to inject a virus into a cat who will have trouble fighting it…?

Again, many thanks for your great website and info. on FIV.


Feline immunodeficiency virus, or FIV, is very similar to the virus that causes human AIDS. There is no evidence that FIV poses a health risk to humans.

Cats with FIV suffer from immune system compromise. A weakened immune system predisposes cats to opportunistic viral and bacterial infections.

Jenny, you make a good point about injecting viruses into a cat with a weak immune system. Some vaccines are made from attenuated (modified) live pathogens. The organisms in these vaccines can in rare instances revert to a pathological state. This so-called reversion to virulence may be more likely in an immunocompromised individual.

However, I would not recommend foregoing vaccines altogether. Although the virus will some day affect your kitten’s immune system, for many years he may respond normally and benefit normally from vaccination. Also, remember that a weak immune system needs all the help it can get. Vaccines are designed to help the immune system organize and prepare for exposure to disease.

To my knowledge no group of specialists has issued specific vaccine guidelines for cats with FIV (if any reader knows otherwise and has a link to such guidelines, please post it in the comments section). In the absence of guidelines, I would recommend the following steps.

  • Keep your kitten indoors. This will reduce his exposure to potential pathogens.
  • Have your kitten re-tested for FIV in six months. Standard tests for FIV can yield false positives, especially in young kittens. Ask your vet about re-testing with a method known as western blot. This method yields very few false positives.
  • Although some thoughtful and reasonable veterinarians may disagree with this (remember, there is no consensus among vets about vaccines in general), I recommend that you follow standard kitten vaccination guidelines for core vaccines. This means he would be vaccinated at 8, 12, and 16 weeks of age. Re-vaccinate at one year of age, and then repeat the vaccines no more often than every three years. Core vaccines include panleukopenia (usually in combination with rhinotracheitis and calicivirus) and rabies (where legally required). If your cat does not go outside he won’t need the leukemia vaccine.
  • Avoid non-core vaccines such as Bordetella and ringworm.
  • Ask that no modified live vaccines be used in your cat. In my opinion killed virus and subunit vaccines are more appropriate for your cat’s circumstances.
  • Stay up to date with feline vaccine guidelines and news. New research could come out any day that might affect your decisions about vaccinating your cat.

Get Catster in your inbox!

Stay informed! Get tips and exclusive deals.

Let Catster answer all of your most baffling feline questions!

Starting at just


Follow Us

Shopping Cart