Adult cats with no known prior vaccination records:
Must be vaccinated twice, with a least 3 weeks in between the shots. The first shot should contain a vaccination against cat disease and cat flu. The second shot should contain at least a vaccination against cat flu.
The latest shot should be done at least 3 weeks ago.
The latest flu shot should be done no longer ago than one year.
Cats having their yearly shots:
Usually their shot will contain a vaccination against cat disease one year and a vaccination against cat flu the other.
Furthermore the shots may not expire during the stay.