Hmmm...Are you worried about vax'es shedding, or just natural viruses being passed around?
If it's about shedding vax'es, the only ones you need to worry about are Rotateq, Flumist, MMR, and chickenpox. They are the only live vax'es that could possibly pose a risk of infecting an unvax'ed child.
If you mean the bigger picture of illness...Sorry to be so blunt, but that's life. There are contagious illnesses being passed around every minute of every day and certainly an unvax'ed child could become infected with one of them. And likely at some point will become infected with something. So will many vax'ed children, for that matter. Germs, bacteria, and viruses are all around us. The best thing to do is practise good hygiene and focus on good nutrition. They are your best defenses againt illness.
PhDin' mama to dd (Oct. 2005)