Today we are going to discuss a relatively new vaccine for cats.  There is now a vaccine available for feline immunodeficiency virus, commonly called feline AIDS or FIV.  This virus is closely related to HIV or human immunodeficiency virus.  However, it has been proven there is no transmission of FIV to people so we do not need to worry about that.  The disease in cats is similar to HIV in people in that clinical signs are related to the disease the cat develops due to the immune deficiency.  Common diseases cats develop with FIV infection include oral infections, chronic skin, urinary tract, and respiratory tract infections. 

Cats usually die from the secondary disease, not from the virus itself.  Transmission of the virus is usually due to bites and scratches and therefore totally indoor cats are generally not considered to be at risk for infection and do not need vaccination.  As for the vaccine itself, it is reported to have an efficacy of 82%. 

However, there are some concerns about its use.  The American Association of Feline Practitioners has made some recommendations concerning the use of the vaccine for several reasons.  Current tests now used in veterinary clinics and some animal shelters for FIV in cats are antibody tests.  Since this new vaccine causes antibody production, the tests currently used will be positive after the vaccine.  Because of this, it will be difficult to determine if a positive test is due to vaccine or actual disease.  Consequently, all cats should be tested and found to be negative before given the vaccine.  It will be impossible for a veterinarian to determine if a sick vaccinated cat is actually infected with FIV or not.  This makes a major difference in prognosis of the case. Also, some animal shelters euthanize stray cats with positive FIV test results.  It is possible these shelters could euthanize healthy but vaccinated cats.  Consult with your veterinarian to get his or her recommendation on the use of FIV vaccine in your cat.