Leukemia vaccination and your cat
The feline leukemia virus is the leading cause of cancer in cats, but not all cats need to be vaccinated to be safe from it. The virus is contracted through contact with an infected cat, so if your other cats have not tested positive for the virus—and if they all stay indoors—there is no need to vaccinate a new kitten that you bring into your home.
However, if any of your cats will spend time outdoors, a vaccination may help provide protection from the virus. And if your cat does test positive for the virus, you’ll need to take extra precautions to help them—and your other cats—stay as healthy as possible.
For example, infected cats will be very susceptible to other diseases, such as upper respiratory infections, so you will need to monitor their health closely. And you will need to keep them separated from other cats, because the leukemia virus is highly contagious.