Booster ShotsWhether your now-grown cat received his first FVRCP shots as a kitten or an adult, he’ll need a booster one year after the initial series and then another booster every three years. If your cat spends time outside or otherwise comes in contact with a lot of strange felines, your vet might recommend an annual booster. The FVRCP is considered a core vaccine, along with rabies shots, meaning it’s recommended for all cats. Your vet gives the FVRCP injection in the right front leg. If your cat develops a rare vaccine-related cancer called fibrosarcoma at the injection site, the leg can be amputated to save his life. An intranasal vaccine is also available.