How Old Does A Kitten Have To Be To Take?

Westside Veterinary Hospital – Dr. Lori Gerstner

The age at which kittens can be vaccinated is determined by the type of vaccine used and its potency. Generally, kittens less than four weeks old are not able to tolerate live vaccines very well, so they receive killed-virus vaccines instead. For example, feline leukemia virus (FeLV) vaccination in young kittens requires that the kitten’s immune system be strong enough to respond to FeLV infection before it can respond to immunization with a live version of this virus; otherwise, there would not be enough time for protection against FeLV during active disease before symptoms develop. Therefore, young kittens typically cannot be vaccinated until after they have demonstrated their immunity through exposure or infection with an infectious agent such as parainfluenza (FIV), feline panleukopenia (FPV), feline herpesvirus-1 (FHV-1), calicivirus (CAV) or rabies virus/vaccine strain (#17).

Young cats usually require two doses seven days apart of FIV antigen alone administered via injection into the deltoid muscle behind the shoulder blade using a 27 gauge needle. After completing the series of vaccinations given at one year of age along with boosters every three years thereafter for life, most adult cats will have received 5–6 rounds of booster vaccinations over their lifetime without any problems whatsoever doing so.

Kittens < 8 weeks old generally do not benefit from being boosted