Hiya
There is no cure for Herpes, but many cats will live normal healthy lives with only the occasional blip. The cats that I know about usually present with vomiting, but there are different strains. It can be contagious, but not always. If your other cats haven't caught it from the mother then they will most likely not pass it on to your other cats. Phone your vet and see if they have any information about herpes that you could read over. Ask to talk to the nurse and see if she can help answer your questions. Many vets have tons of book on diseases and viruses and some will even photocopy sections for you.
Cheers
Kim