I dont think their are any serious issues with unvaxed children, just like any other illness they will show signs and symptoms of any sickness/illness, and you will treat it as you do a cold or flu per your contracts. no immunization is a personal choice due to religion or other beliefs, I dont think you are putting anyone in any danger by having an unimunnized child around, you just have to be as proactive as you should be with all other kids and stress to all parents the sick policy. any signs or syptoms of illness? the child stays home or goes to doc. ultimately, it is your choice though, and if your not comfortable dont take the child.