Unfortunately there is no definite answer to this very common question.  Many current studies show that cats and dogs have sustained protection from routine vaccinations that are given every year.

I am suggesting to owners of older pets that they consider not vaccinating and in addition requesting a titer check.  A titer is a blood test that indicates a level of antibodies (cells that protect mammals from disease).

It is not a 100% guarantee that your pet is protected, but neither are vaccines guaranteed to be 100% effective either.

In fact we know that in cats, we see a problem called injections sarcomas.  *, which we suspect is due to a reaction from vaccinations either from the site (usually the neck) or what is in the vaccine.

* Please see injection sarcomas.