These are viral diseases of cats that can cause serious illness, including death, and are easily transmissible. Transmission can occur from cat to cat contact, or from exposure via an infected environment. This is considered a core vaccine, and all cats should be kept current on this vaccine.
Start series at 6-8 weeks of age and booster every 3-5 weeks until 16-18 weeks of age. Booster annually thereafter until 3-4 years of age, and every 2-3 years thereafter. If series begun after about 3 months of age, only 2 vaccinations necessary, 3-5 weeks apart, for initial series.

Rabies is a viral disease that is transmissible to many other animals, including dogs, cats, livestock and also to humans. It is a core vaccine, and all cats should be current. There is no cure for Rabies, and it is a fatal disease.
First vaccine at 3 months of age. Booster one year later, and every three years thereafter.

Feline Leukemia
This is a viral disease unique to cats, and transmissible via direct contact such as mutual grooming or eating out of the same food dish. It can weaken the immune system and leave the cat open to other fatal diseases. It has also been associated with lymphoma.
Best to test before vaccinating. Start series at 10 weeks of age. Booster 3-5 weeks later, and annually thereafter.

This vaccine enables the cat’s own body to create antibodies against Western Diamondback rattlesnake venom, and it is thought that this will mitigate the severity of a rattlesnake bite, should one occur. If a vaccinated cat is bitten by a snake, the cat should still be examined by a veterinarian as soon as possible. The vaccine is administered only to cats at risk for snake bite.
Start series after 4 months of age. Booster every 4-5 weeks, two more times, for a total of three vaccines. Booster annually thereafter, preferably in the spring. If any annual booster is missed, series must be repeated.

FeLV/FIV testing
Feline Leukemia Virus and Feline Immunodeficiency Virus testing can be done at any age and is highly recommended, particularly when introducing a new cat into a multi-cat household. If a positive FIV test occurs in a kitten under 6 months old, the test should be repeated at 6 months of age. For this reason, many people choose to test for FeLV only in kittens younger than 6 months.