In , "PattyC"
wrote:

| A friend of mine has somehow taken in a kitten who has Calci virus.

Calici is the 'C' in FVRCP, the triple combo vaccine shot.

| She has 3 other indoor cats. She's been keeping the kitten separate,

This is very important. Calici is highly contagious, so stringent
quarantine measures are essential. It can survive in the environment
for days if not weeks.

| She wanted me to ask you guys, can this kitty ever join the others,
| or is this something that will endanger her own kids.

There are two factors here. Whether the other three cats have been
vaccinated (it takes at least 10 days for the vaccine to start working)
and which particular strain of calici this kitten has. In any case, the
kitten will be a "carrier" for life.

http://www.winnfelinehealth.org/health/calici.html