Why shall we vaccinate the cat? After all he is always at home…
The vaccinations of the cat are not obligatory, except the one against the rage if the cat travels with his owner in particular risky areas by air or by sea (in these case we should inform with every companies before) or simply requested by some catteries.
In general if there are no other risks (endemic zone because of particular pathologies) we submit the small cat to the first vaccination so called Trivalent at the age of 2 months with a recall after 30 days. It will be enough to repeat it with a single dose every year or every 2 years according to the habits of life of the subject, only domestic or stray life.
Your veterinary will suggest you the best vaccination program for your cat. There will be a proper argument for the vaccination against the feline leukemia, destined to some only. To avoid vaccinations completely is however wrong since, even if our cats are often a home, we go out and with our shoes we could take pathogen viruses which could make them to get sick very seriously, I remind you that many pathologies are fatal.