Vaccination and immunization are used interchangeably but they are not identical in meaning. The proper use of vaccines will provide kittens with the best amount of protection against devastating and potentially fatal feline infectious diseases. Kittens receive protective antibodies from their mother's milk. This is called maternal immunity. These antibodies begin to wear off between six and ten weeks of age.
Vaccination typically occurs at six to eight weeks of age in kittens.
The kitten's maternal immunity prevents immunization from occurring if vaccines are given too early. When the maternal immunity decreases, the kitten may then be successfully immunized through vaccinations. The maternal immunities decrease over a period of weeks, so vaccinations are spaced out from six to twelve weeks of age to permit the kitten to build up immunity. A vaccinated kitten may show signs of fatigue, lack of appetite, may sneeze or have watery eyes after vaccination. Kittens should also not be given multiple vaccine injections at the same time.