I have indoor outdoor cats.
When they were just indoor cats (neighborhood not appropriate to letting them outside) I did not vaccinate them. As soon as it became apparent that they could go outside again, (new area) I got all shots up to date before letting them out.
All of them as kittens were given the proper shots. I did not find any negative effect on not giving them shots when they were indoor only.
Rosie - 1999
Callie and Tigger, brother and sister - 2001
Akira - 2010
Peanut - 2010
Spencer - 2013
Trey our 3 legged terror - 2014