The vaccine industry for felines has been thorough advancements in the last 20 years. Most specifically, the American Association of Feline Practitioners (AAFP) developed guidelines for veterinarians to follow regarding when and where to vaccinate cats. Some vaccines, including Rabies vaccine, are now available non-adjuvanted meaning without a carrying agent that was previously administered in years past and carried the risk of cancer. These non-adjuvanted vaccines are worth the extra expense to assure a safer outcome in vaccinating your cat.
Vaccination protocols vary by practice but it is my recommendation to have all kittens given booster vaccinations every 3-4 weeks beginning at 6 weeks of age and continuing until 12 weeks of age. This allows the kitten to develop its own immunologic response to the vaccine and prevents interference with maternal antibodies. Older kittens need two vaccine boosters given 3-4 weeks apart. An adult one-year old cat needs their annual booster and then vaccines should be administered based on a lifestyle analysis and risk exposure.
I like to administer the Rabies vaccine in the right rear leg close to the ankle (hock), the Leukemia vaccine on the left rear leg, again close to the ankle, and the FVCRP (upper respiratory) vaccine between the shoulder blades. This allows a good distribution of the vaccines so that your cat is not overly painful in one location. It also follows the guidelines set up by AAFP. I always recommend vaccines be administered by a trained professional. Veterinarians are confident in the manufacturers they purchase from and know how to properly store vaccines.