Also jumping in on the topic of the FIP vaccine...
Current research suggests that FIP is caused by the mutation of the feline enteric coronavirus - a coronavirus which virtually 100% of ALL cats - both domestic and wild - have been exposed to. It is when THIS virus mutates into FIP and when the cat's immune system does not fight it off that a cat becomes infected with FIP. Only 1% - 2% of the general cat populace which have been exposed to FIP actually ever develop the disease. Even in shelter and cattery situations, the incidence is no more than 5% - 10%. There is absolutely no value in isolation of the cats. Furthermore, there is absolutely no value in running blood work, since either the cats will fight off a challenge to their immune systems or they won't. Certainly feeding them a good quality food and giving them immune boosters (such as echinacea) is good for them but will not help nor hinder their own ability to avoid developing the disease.
FIP, although discovered as a separate virus back in the 1960s, is still not well understood, and it is only recently that research has pinpointed what appears to be the cause. However, there are no definitive ways to prevent the disease (other than, reportedly, total isolation of a kitten from its mother and all other cats starting at about 3 weeks until it is roughly 16 weeks or more) and I wouldn't touch the vaccine with a 10-foot pole. The problem with the FIP vaccine is that it is to be given to cats which don't have FIP. The problem with that is that there is no such thing as a test which can tell you whether a cat has FIP or not prior to administering the vaccine, and there are reports of the FIP vaccine causing full-blown FIP.
Just my $.02 US,