In sum, if you know your cats are seronegative, and they are older than 16 weeks, the vaccine is recommended by both the Cornell Feline Health Center and the consensus reached at the Winn Foundation sponsored FIP/FECV seminar. If your cat is already seropositive, there is not much evidence that the vaccine will help.

The vaccine will be more of a help when

• the manufacturers demonstrate its effectiveness against the Type I strain of FIP
• it is shown to be effective in seropositive cats, and
• it could be shown to be safe and effective for kittens under the age of 16 weeks.

However, it appears that there is work being done to develop a FECV vaccine. Preventing FECV infections in the first place, and thus preventing FECV from mutating into FIP, might turn out to be another technique in trying to protect against FIP.